Gentle Singing Warm Up - Bass Baritone Range

[@sugarqbs]

Scales: 1:13-2:58 "E"-"A": 3:38-5:25 "E-"oo": 5:45-7:27 "A"-"O": 7:44-9:24 "oo"-"A": 9:34-10:59 "O"-"A": 11:09-12:01

[@davigramostini1336]

Thanx!

[@catedoge3206]

Thanks

[@michelle3585]

This is a a frozen piece of art and beautiful art I can relate and and many more! thank you sweetheart for your share! Your a beautiful person. Your videos gave me hope on singing. I thought and might have. But try to recover from so long ago. I still can hit just about every note you throw at me.

[@tenesinsixtiliev]

I - E I - U E - O U - E O - E **

[@LPbeater]

Im only 2 months old and i sang all the way through!

[@maolruanaidhh9153]

Armadillo Studios woooooooosh

[@d3ad.4gain]

Armadillo Studios Wooooooshhhh

[@dillon1012]

Lol fetus

[@mikecassidy4637]

WTH hilarious

[@mikecassidy4637]

WTH hilarious

[@jujubean9063]

I do this everyday when I wake up. I have noticed a huge improvement in my pitch control and tone. Jeff has the best Bass-Baritone exercises on the internet. Thank you Jeff Rolka!

[@JeffRolka]

Fantastic!! Thank you for watching! Thank you for singing with me! Jeff

[@chooha]

Agreed

[@catedoge3206]

On God

[@jamesirwin8917]

YesJulu. Jeff's exercise here really helped develop my lower baritone range. Jeff's great a great vocal teacher. Wish I lived nearer to him.

[@justJulian..]

When i first started I could only sing as low as a F2 or E2. Now i can sing as low as a D2 and on a good day i can sing as low as a C2. Thanks for this exercise Jeff I'm glad my bass voice is finally improving

[@bradycowles5520]

Damn you dropped a whole 5th! Does it feel a lot more comfortable to speak as well now that you can go lower?

[@Rednaxela137]

Wow wish I could increase my lower range but can’t….six years ago I was told I’m a low bass and was able to sing an Eb2 on demand with breath support; however i couldn’t sing any lower…. now that I’ve been working on my upper range and mix voice I lost that note and can only sing it in the morning or if I’m sick

[@Hope-qy9nr]

@@Rednaxela137 my lowest note is a b1 and my highest is a f4 but I can hit higher notes in head voice up to a g5 but my headvoice comes and goes lmao

[@victorrodrigues5674]

​@@Rednaxela137If you could before then you can now! Your vocal cords only get thicker when you grow up because of testosterone, and also your larynx plays a big role on it. It's typical to lost your high notes, but don't give up! Probably your range changed so your body needs to adapt to your new range now

[@SiyaTheeInertV10LIN]

my lowest used to be c2, but i managed to get it to A1

[@Yitzhakhazak]

The most important concept is "comfort". If you can sing comfortably between the low F and the f two octaves higher, you are a low bass-baritone, also called a basso cantante. Plenty of Verdi and other Italian basso parts for this Fach. Some basso singers, like Boris Christoff, have even sang Sarastro and Wotan. Such bassi can even sing up to an a. The higher bass-baritone can sing like a dramatic baritone, dark and powerful. Power and staying power in the upper register is typical of such baritones. So let comfort, tessitura and timbre (klangfarbe) decide. This you have to find out yourself. The extreme tones, low or high, do not show that. Start your warm up with bocca chiusa, closed mouth, exercises. Don't bite your teeth. Loose mouth. Small round tone to begin with. Good luck.

[@Theman-mp2vm]

So you mean between f2 and f4

[@Daniel_Muniz]

My tessitura is Eb2-E3 I sing comfortably in the 2nd octave. I can hit F4 as well, but it's a bit harder. I believe with train and practice, I'll get there.

[@stevebismarck5878]

Vocal range does not qualify one as a basso cantante. There are plenty of low basses who are bassi cantanti. The defining characteristic of the basso cantante voice type is high tessitura, which is a quality more typical of higher voices such as tenors or sopranos. If you are a bass and have unusual facility in your upper register -- if you can easily sing songs like "Cantique Noel" or "The Star Spangled Banner" in a mid-voice key and sound good doing it -- you may be a basso cantante. The average bass-baritone is not a basso cantante. The term refers to relative tessitura, not range. True bassi cantanti are quite rare. They typically have vocal folds that are very long but not that thick.

[@walterkilos]

It is true that each bass baritone has its comfort, we must sing in our comfort. In my case, I feel very comfortable between a D2 and C4, and I feel more comfortable in low notes like C2 than in C4, and I usually sing in a more comfortable area like C2 and A3 which would be very pleasant for me. My voice has a baritone tone and a strong bass, which is why I think I am a low baritone bass.

[@gstoe5560]

I love hearing Jeff say "don't do jumping jacks if you have any, you know, issues" every morning XD Thanks for the daily warm up! So helpful. I'm 3 and a half months into my singing journey and seeing fantastic results. Thank you!

[@MetzJnr]

Never do jumping jacks as my issues are so broad 😅

[@canaldocas]

is so hard to find material about bass baritone! thank you so much! keep doing material for this range!

[@JeffRolka]

Will do! Thank you for watching! Jeff

[@daybydayvon1194]

Best vocal coach ever

[@JeffRolka]

I try my best! Jeff

[@garybrown5655]

Thanks for your help with us bass baritone singers .we now have Chris Young and Josh Turner to add to our lists of greats

[@ADubbs-fd8xf]

These are the least toxic comments in all the interwebs, my thanks good people

[@erarung28]

🤪

[@bcast3000]

Thank you Jeff!

[@zacharywho5442]

2:50 that smile at the thought "Y'all still keeping up?"

[@louislark4506]

Jeff Roka you are a phenomenal vocal coach.

[@quintinpace2627]

D2/Eb2 crew reporting in

[@JeffRolka]

;-) kzbin.info/www/bejne/pF7cY6Jmf99opcU Jeff

[@Conker32192]

yessssss me!!!

[@makr-thefabuloussonofgod1729]

Been developing my lower range as a Dramatic Tenor for years now I can reach C#2 but It sounds like Avi Kaplan burped

[@KaentukiTheFuki]

A0 crew reporting in lmao 😂 video not low enough!

[@makr-thefabuloussonofgod1729]

+Shane Echuveria no cheating using vocal fry!

[@bradycowles5520]

All you guys with these half octave voice drops going on are lucky. I’ve been struggling to get below E2 for over a year

[@joerogers7000]

Might start lucky. I'm ten years now missing the A1-C2 I had when I was 18-19.

[@jeremiahromagnoli7389]

You aren't a bass-bari then

[@jameslester3800]

As a bass baritone, this is by far the best warmup that I have ever found. Thanks so much for sharing

[@walterkilos]

x2

[@ireallyhatemakingupnamesfo1758]

I love your enthusiasm and energy in every one of your videos

[@edwardmeradith2419]

Hey, I'm just another dan of Jeff's videos -- but had to say you have the BEST user name :)

[@HSTS_Mari]

I HIT C2 WITH COMFORT LIKE WHAT!? I WASN'T ABLE TO DO THAT BEFORE!

[@mateoteoteo753]

TheSleepyWaterBottle how low this exercise goes? Lol i wanna know cause i made all the exercise comfortably

[@mateoteoteo753]

Niranjan Rajesh WHAT? I can't believe it!!!!! I was only able to hit D#2 straining, and this exercise made me get lower than i thought i could...

[@mateoteoteo753]

Niranjan Rajesh nop, i actually noticed there's not fry

[@status8477]

maybe you did this exercise with your morning voice?

[@kreole7376]

I usually hit D2 but this time a full C2 it's amazing.

[@halomaseko752]

OMG im using this warm up everyday and i can hit B1 on 10.00am, big thanks jeff :D

[@iandavis2819]

Sama bro btw saya juga bass-baritone.cheers bro! ✌

[@DarkLord852236]

Thank you for this gentle warm-up, your positive energy is what makes your video different than others

[@JeffRolka]

You are so welcome

[@basscoot]

just blasted my first D2 in forte and my first E2 in fortissimo thanks a lot, mr rolka

[@giomckenzie7]

I found this useful for a light warm up before recording a song or scale for my choir class. Thank you.

[@bkwilco]

Great exercises for getting back in shape after almost two years off from covid! Thanks!

[@bicaldoralphlawrences.4566]

I downloaded this video seven years ago and still practice singing. I learned how determined I am to study and explore more about music and singing. Vocalization/s are really important while singing in a choir, and I miss our Conductor, who taught us to be passionate, competitive, and sing with love. Thank you, sir. Jeff Rolka! P.S. I'm back looking for more of your videos to learn and practice vocalizations!

[@Lian_music]

Is it possible for a bass- baritone to sing high? Like actually that it sounds good

[@KalliDavies]

​@Lian_music of course it is! You just need good alignment. Jeff has several videos that cross the passage to get into your high voice.

[@scottunique]

truly appreciate the effort in putting these things out and making them available. You have made me a better singer and I thank you:-)

[@bluecosmo.]

i love how low you went in these, usually my lowest notes are not covered w teachers online

[@roccodicardielli]

OMG Jeff you have so much! Thank you for these posts and your dedication to helping those of us who wish to make ourselves better. Ignore toxic comments as their discontent is obviously due to jealousy and your following is proof of it! Thank you!!! 🙌🏼🙌🏼

[@thomassicard3733]

Thanks, Jeff. I am going to keep trying to hook into my voice. Low baritone. Pianist all my life. Professional pianist abd French hornist for many years. Voice is the greatest 'instrument'.

[@jasondotj]

Thanks for including some low note exercises, Jeff! Of course, I couldn't get as low as you went (I think the lowest I can comfortably sing is around F#2), but it's nice to work the lower register.

[@JeffRolka]

Hey Jason! So nice to hear from you! I put some bass range notes in there because I had a few requests. Future baritone warm ups will include them to a certain degree; just remember to take a short break when it goes too low! Jeff

[@seventeenducks7212]

One of my go to warm ups, this channel is great!

[@anthonybielik287]

I'm about to go on AGT with Voices Of Our City Choir. These lessens are helping tremendously! Thank you Jeff Rolka!!

[@catedoge3206]

Ayyye

[@donovanackleyiii]

Congrats, Anthony! I think Andy (your VOOC director and my voice teacher) might have introduced both of us to Jeff's helpful warmups!

[@obwivion]

thank you a lot!! i could kinda sorta get down to the last C2 using this exercise, ive only ever barely gotten a D2

[@PeterHenrichsen]

This was SOO good to my voice, starting this way after a cold. I won't be the last time this video will help me out! Thank You, Jeff Rolka, best wishes from Copenhagen, Denmark, Peter

[@JeffRolka]

Excellent! You're welcome! Best wishes from California! Jeff

[@lommedepauw9291]

Hey man, I've only recently stumbled upon your videos,and I'm really liking them! I never had any vocal training, and normally I would only get down to E2. But with your help, i'm already starting to get even lower, and hitting that Eflat or even the D! Thanks!

[@JeffRolka]

Awesome! Thank you for taking the time to let me know about your progress. Please keep me in the loop! Thank you for watching and enjoy the channel! Jeff

[@louislark4506]

Thanks immensely Jeff for your didactic singing pedagogy.

[@GabrielPoliglota]

This is fantastic!

[@jonathanakehurst4489]

Good morning from Stuttgart! Just checking out this mellow exercise...

[@JeffRolka]

Hello Stuttgart! Thanks for watching! Jeff

[@eddiesushi]

Thanks for existing.

[@beaubarrett1355]

Thank you so much!! I'm playing Javert in Les Mis and this is a lifesaver!

[@stevenwashington7835]

Thank you thank you thank you! I love and need this so much.

[@JeffRolka]

You're very welcome! Thank you for watching and enjoy the channel! There's a couple other gentle warm ups out there too, just fyi! Jeff

[@dagurgisla1944]

"Don't do jumping jacks if you have any...you know, issues." Haha. Solid advice!

[@PannenbergMusic]

I think my floor just crashed... XD

[@wojciech4708]

Thanks for your videos Mr. Jeff. I got few singing lessons few years ago. Now I learn playing piano and thinking about return learn playing recorder. Your singing videos/lessons helps when I want singing sometimes as hobby(I like[maby even love] singing but more love playing on music instruments) and your videos helps when I am tired of play piano and want take brake from it and singing as hobby. I was dramatic baritone so baritone with super low peaches. Now I am finally bass-baritone. Have a good day for you Mr., other commentators and readers.

[@louislark4506]

Jeff Roka you are a phenomenal You Tube vocal coach. Thanks!

[@matthartman19]

Absolutely fantastic, I love the pacing. Thank you!!!🤘♥️

[@chadthomson4596]

I understand this better than before. Listening to the backing track guys across the street right now. They haven't the foggiest. Humility inspres. I feel connected to historical singers. Canada has no competition.

[@GameInDorf]

I absolutely love your channel and the way you do these exercises.

[@JeffRolka]

Wonderful! Thank you for that! Jeff

[@gabrielbeltrame1083]

recovering from a cold, having a lot of fun and learning with this video . thanks a lot! subscribed, yeah!

[@JeffRolka]

Thank you so much! Feel better and take your time with your recovery! Jeff

[@IllicitxDSz]

These warmups are excellent, thank you so much!!!

[@DanielJoseMP]

Thanks from a basso profondo

[@benson3955]

Daniel Martinez please teach me your ways. Honestly tho, anything helps.

[@ghettosupahstar3024]

I've been practicing with you since summer but in the past few weeks I have really gotten consistent and I can finally say i got the low start almost effortlessly with great resonance :D (even on A-->O where I usually have the most trouble) Thank you jeff!!!

[@JeffRolka]

Fantastic! Keep it up! Jeff

[@KCOMSUPPORT]

"This rules"; large...what a gift ... Thanks!

[@Edwinkev]

Thank you Jeff!

[@rylanpeery1925]

Favorite way to start my day...

[@robertjensen30]

Thanks for putting this up, Jeff! I've been waiting a couple months to have it, so that I can train my vocal fry like I did with my falsetto. :)

[@JeffRolka]

You're welcome! I'm going to start extending the baritone videos down into the bass range as a general rule! Jeff

[@orlandoortiz9233]

Hey Jeff! This is an excellent video. This is what I was looking for. Thanks for including those low notes. It is a really good warm up, specially for a bass like me. Greetings from Colombia!

[@JeffRolka]

Hello from California!! Thank you for watching and I'm really glad you're enjoying the video! Yes! About six months ago I started including additional low notes to cover bass-baritone range in the baritone videos! Enjoy! Jeff

[@lldmapolinarquistianzamora1777]

2024 anyone ?

[@roccodicardielli]

I use this nearly every day for now two years

[@PureSaji]

✨ Daily gang reporting in ✨

[@jaakkot9661]

Thanks for this great video! I'm going to do this every day.

[@venus.2148]

THANK YOU, THANK YOU THANK YOU.

[@jameshawkins8817]

Awesome video, thank you. I find that the higher notes used in this exercise were very comfortable for me, but the lower notes gave me a hard time. I could reach the right pitch relatively easily, but I had difficulty getting enough air behind the lower notes to project properly.

[@otaviosantosdealbuquerque]

Thank you so much, this has helped me a ton!

[@MrMark28]

Those Low notes hit the spot!!

[@JeffRolka]

Yeah baby! Low low low! Jeff

[@sadreality9803]

Jeff Rolka your the best

[@breadtoasted2269]

Your channel is blessed

[@xblts]

Amazing job and amazing technical parts to warm up! Excellent!

[@vikroy3777]

I would say I'm a baritone but powerful down to F2. I wouldn't class anything below E2 as part of my range as it starts to become vocal fry, but, I enjoy singing low notes and I'm finding doing this warm up daily is helping to make those low notes feel a bit more solid.

[@bilbobaggins2265]

Very much appreciated this warm-up exercise. Thank you. I've sent ther link on to my choir director.

[@natalierozean5989]

I’m a female. Thought I was an alto. My family always complained , because when I barely raised my voice, the entire neighborhood could hear me resonating. When I was mad and raised my voice… They were afraid the windows were going to break. That is not over exaggerating. I knew I talked in a low voice. I knew in high school that that I sang best along with Eddy Vedder in Pearl Jam. Recently, I got tired of everybody telling me I was too loud… Way too loud. So after hearing with practice I could hit high notes and maybe not be as abrasive, I decided to study vocal lessons on KZbin. And yeah… I went completely opposite of what my family wanted. I immediately discovered I could sing Hoist the Colours with outstanding resonance and low enough to make the jolly green giant jealous. My husband… Just shook his head in disbelief and surrendered. So here I am… Trying to learn bass warm-ups instead of alto warm-ups. had no idea I was a bass. My husband is a bass, although he plays the upright bass and doesn’t sing. His family is incredibly musical. I, on the other hand have no idea what I’m doing. I can’t imagine the time or situation that someone will need either a Death metal growler a bass singer or someone to beatbox and call upon me. 😂 but this is super fun!

[@jasperbarnhart9598]

I can do most of this exercise, 9 months of testosterone!!

[@jjth3k1d]

I'm 5 years in! Gets easier and easier, just keep singing 😁

[@0verw0rked.Art0]

Doing these exercises to try to practice androgynous voice :)) good luck!

[@c.m.6837]

Keep it up. 6 years in, finally getting classical Baritone solos! In the beginning, my voice cracked so much I thought I'd never sing again. Finally have the voice I always wanted.

[@Frankcoam]

Congrats!! **deep voice**

[@nathanscore]

almost 4 years on t, i was too insecure because of my voice to learn to sing before it dropped. now i know i have a lot to work on but it's a pleasure to see trans brothers trying these exercises too! 💜

[@catedoge3206]

Day 1 of vocal warmup daily: July 10, 2020 - I feel optimistic. Edit 1: Been doin some other warm ups but been doing warmups everyday. Definitely helps. Edit: im back apr 1 2023 10:15 pm

[@JeffRolka]

Awesome! Keep me in the loop! Jeff

[@delta61]

I wasn't even planning on singing today, initially I was trying to find out how low the baritone range goes. But then I just went with it and did the whole warm-up, I felt like the Bob Ross of singing was talking to me :)

[@JeffRolka]

High praise! Thank you so much for that! Thank you for singing along and being here! Thanks so much! Jeff

[@vandemonia]

Another absolute banger from JR

[@JeffRolka]

Thank you!

[@chooha]

I admire everything about you, master !

[@0verw0rked.Art0]

Have been starting to do these voice exercises to make my range larger and in the hopes that by habit my voice will be lower! I'll update in a week :) so far my throat is sore but the good kind.

[@JeffRolka]

Be careful of the sore throat! Keep us in the loop! Jeff

[@OctavianGray]

Man you are the best. Respect and thanks

[@adryanrosa4473]

thanks, Jeff

[@armadillostudios2720]

Jeff, I come to you today furious, and immobilized. When the notes got too low, I decided to perform jumping jacks as you had suggested. And you know what happened? Well, I have some physical troubles in my shoulder region, and I ended up dislocating both my arms! I struggled to cope with the pain, and while doing this, I stubbed my toe, falling to the floor and dislocating both my legs! And that's where we are now. Other than that, 10/10 video, liked and subscribed.

[@JeffRolka]

So - is what you're saying is that it's but a flesh wound? kzbin.info/www/bejne/i5rNmZV-q92KqKM

[@m.lindemann8400]

@@JeffRolka Ii thought of "tis but a scratch" before opening the video 😂

[@Wallhackingplusesp]

Im surprised I went down as low as I did, I usually can hit C2 but this time I got B1 😂

[@MsBodzioch]

Me, too.

[@vennar32]

SAME

[@bradycowles5520]

Damn Phil Anselmo in the house

[@gperkins1080]

Thanks for adding the lower notes. Can you please tell me what is the highest note you reach in this exercise?

[@JeffRolka]

I think it stays below A3. Jeff

[@gperkins1080]

Jeff Rolka great thanks

[@AllanEvansOfficial]

Jeff you’re a legend

[@JeffRolka]

Very kind, thank you for that! I do my best!

[@xyzt123456]

Thank you, thank you very much indeed!

[@plusalberto]

Tanks for this gift!!! 🙏🏽

[@makr-thefabuloussonofgod1729]

Dramatic Tenor dreaming of a lower register squad here (My Lowest Is C#2)

[@carlosnoguera413]

Makr - The Fabulous Son Of God 😂 you got that right

[@makr-thefabuloussonofgod1729]

Stop it with the emoji's

[@paulmanlapig2494]

My lowest is g#1 and im just 15

[@wayneching6850]

Paul Manlapig my lowest is C-100000 and im just 3

[@imabbas76351]

I'm 18 and my lowest is F

[@zleenacoironet7674]

Best exercise for my voice i can sing very comfortable with the low notes

[@rylanpeery1925]

Hey Jeff! No pressure but if you ever felt like updating this for patreon with a gentle morning vocal warm up, it'd be great to have access to mp3s and maybe even a longer form version of this... For your episode idea list. Thanks as always for all that you do!

[@JeffRolka]

Sure! I haven't done one of these in awhile! Happy to oblige! Jeff

[@Jasongs]

Great stuff ..thanks Jeff

[@JeffRolka]

Thank you! I appreciate that! Jeff

[@jonathanakehurst4489]

Love it man! Thanks from German Jonny. I'm feeling mighty loooow...

[@JeffRolka]

Nice! Hello from California! Thanks for watching! Jeff

[@status8477]

I'm really sad right now. If I sing or hum at all for any period of time, I get acid reflux/heartburn/throat burn. But I need this in my life! IT HURTS!!

[@BloodPlusPwn]

I can sing the low notes if I am just singing the low notes, but when I try to move my voice any like sing these scales suddenly the low end of my range disappears. It's rather annoying. Thank you for the warm up.

[@nahumo3271]

hahaha really like how you are smiling and laughing at 2:52 ahhahahaahha

[@Mirumbacubana]

Thanks Jeff. Gracias!

[@rylanpeery1925]

This is a classic.

[@OklahomaLubeDude]

Thanks man, much appreciated!

[@Daniel_Muniz]

I just loved it. It helped me to access my C2 more easily. I will keep practicing. One question: My range is C2-E4 I also can hit A1-E1 using subharmonic. I feel more comfortable singing in the second scale (B2 below). Am I a bass baritone or just a baritone? My low notes also have resonance (not a strong resonance, but they have). Thanks for sharing this video. It helped me a lot!

[@dmytrotsvyntarnyi799]

Most likely, a bass-baritone

[@ljwhittington8044]

Hey, Jeff. For the past few months, I've been listening to your link on Spotify. I'm coming from a trach. cord for 2-4 months to deal with a car crash which resulted in a traumatic brain injury. Shit happens, yes. The cord cut off my vocal tones and I have grown into a commentator on the radio, a speaker in a few other categories, and a singer as well (hah, who doesn't love a good belt eh?)! I follow your bass, baritone, and tenor lessons and I'm really noticing alot of gains from these vids and your lessons, thanks! Keep up the great job! Slàinte!

[@DanDanPlaysMusic]

You should do a basso profundo warmup

[@topcopwatch]

Thank you for the surly smile! 😅

[@MsBodzioch]

Thanks from dramatic bass baritone, too.

[@JeffRolka]

Gotta show some love for the low pipes! Enjoy! Jeff

[@MsBodzioch]

@@JeffRolka I must be in true with myself and yourself Mr after my comment. In fact, I am dramatic baritone not dramatic bass baritone. My school choir professor told me that 2 years ago, but... ...and I don't want to fight with nature anymore. Our voices are instruments making by DNA from our ancestors. My range is D2 to E#5. My music teatcher say that I have good dramatic baritone and Wojtek don't devastate it. I want to be myself. Polish music coach mr boguslawski tell in one of his article on his internet page: "If you are lyric baritone you cannot be dramatic tenor. If you are lyric mezzosoprano, than you cannot be lyric soprano. Baritone is baritone. Tenor is tenor. (...) Voice transposition can only kill your voices, not only singing voice, but maby speak voice, too. Just accept and love who you are, be Yourself and singing well." :)

[@m.lindemann8400]

@@MsBodzioch dramatic baritone is also low. Low enough at least. I'm a lyric bass-baritone and it's almost the same (almost) than a dramatic bari.

[@josephsmith8358]

In the first exercise, I got a little nervous when you kept going lower lol. C2 is my absolute bottom note that I can do healthily..... for now lol.... but when we arrived there, I was like "oh no.... is he gonna go for B1 *sweats nervously*.... oh thank God" lol.

[@JeffRolka]

Love it! Gotta take care of those low tones! Jeff

[@sebastiankrupa_]

Thank you very much!

[@burhantore4807]

you are the best! thank you very much

[@robinrobb3061]

What a nice guy!

[@mikeylesher6722]

Jeff- “mover your body around and wake up” Me- *driving to the studio at 9:45pm completely exhausted*

[@JeffRolka]

All too frequently the case. Still, a little movement can help! Jeff