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I recently unlocked Ukulele Lead level 5 and it introduced alternate picking. When you're alternate picking, are you supposed to be alternate picking the whole song or just the fast parts? And if not for the whole songs, what do you do the rest of the time? Switching back to picking with your thumb (which has been my default thus far) seems hard from the comfortable position to be alternate picking in.

When I'm picking with my thumb or when I'm fingerpicking, my forearm of my strumming/picking hand (left since I'm left handed) is resting on the left of the ukulele just a bit above the center line. When I try to alternate pick, I need to move it up a few inches so it's on the top of the ukulele in order to be comfortable. This makes switching between alternate picking and anything else hard to do quickly. I'm not sure if one of those positions is wrong or if everything is supposed to be done from one position or what.

Are there maybe videos on YouTube or somewhere which demonstrate alternate picking? I've been looking, but am not finding much yet.
This could be the blind leading the blind cause I'm not much further ahead. I started picking by assigning a finger to a string. The same finger always picked that string. It is was better than using a thumb and it works great until you really start speeding up.

From guitar and Uke vids I've seen about building speed, alternate picking is the way to go so I've started working on that. I still use my other fingers from time to time but I find that my thumb is always the slowest and usually only use it for pinching double stops.

I'd suggest going back to the easier songs and work you way through using alternate picking. It won't take you any time at all to work your way back to where you are and you will probably only rarely use your thumb again.

If you are keen you can also learn some scales and practice by alternate picking them. It teaches you how to jump around strings and makes learning new songs easier as you have usually practiced the shapes before. I use Major, Minor and Blues scales all over the fret board for about 10 mins a day. Has helped me beyond measure.

Of course like I said I'm not much further ahead so if others debunk what I said then throw it out.
So, if I follow your advice then this looks something like this:

The thumb isn't picking strings. It's probably mostly serving as an anchor on the body of the uke. Then the fingers aren't assigned to specific strings, but (at least when strictly alternating) the next finger plays the next string which needs to be played regardless of which one it is. (And probably the next finger is getting ready for the next note if things are going fast enough that you need to be planning ahead like that.)

Sound right?

Do you recommend any of the videos you've watched on the subject?

This is the main one I watched. It's for guitar and it includes hammer ons and pull offs.

The same principles apply for the uke but I alternate the fingers and walk them around the strings for the scales as well as using the above exercise. I saw this in another video for ukulele techniques but I can't find it. Ukulelezen is a good youtube channel and so is Ukelikethepros and Tenthembspro for vids on learning new techniques and songs. Ukulelezen sounds like he's talking to a foreign call centre sometimes, but they can all play and have heaps of content for free. I haven't even scratched the surface really.

I wouldn't anchor the thumb on the uke. You will need it sometimes. If you practice with the thumb on the uke it will be too hard to use when you need it. The strumming hand should hover over the strings with no contact on the uke. If you need to stabilise your hand squeeze the uke between your body and your forearm where ever it is comfortable. Or you can consider getting a strap if it really bothers you. If you absolutely have to touch the instrument with your strumming hand I'd use the pinky.

Of course for every rule of thumb (I'm Punny), I bet you can find a pro that breaks the rule but I recon you'd go a long way to find one who is predominantly using the thumb for anything. Don't get me wrong, you will still need it and theres plenty of times where its good to use but it's not your go to. I still have quite a few songs where a assign a finger to a string, I probably didn't explain this well in the previous comment but it looks like the below -

G string - Thumb
C string - Pointer
E string - Middle finger
A string - Ring Finger

Each finger plucks the assigned string only. (ie - Aint No Sunshine When She's Gone, House of the Rising Sun)

When a song needs to be fast though, alternate picking with the pointer and middle finger has the highest ceiling for speed, particularly if there are a lot of notes played consecutively on the same string (ie - Fur Elise, Under the Bridge, Cotton Eye Joe. I'd be stunned if you could reach top speed on these three songs using any other method but my wife has an extensive list hidden away of all the times I've been wrong so I don't know why I am still so sure of myself.)

Also like I said previously, I use the thumb and pointer finger for pinching double stops, you will need this on a lot of songs where for example you need to play notes plucking only the C and A strings (Think - Sloop John B, Waltzing Matilda)

To be honest, I'm impressed you got to level 5 using your thumb as default, you have probably practiced with it more than me and may be far better with it than I can understand. My advice is based on what has worked for me so far and may not be right for you. I'm hoping someone with more experience chimes in and offers alternatives or supports what I've said.

One last thing I've seen but it doesn't work well for me, but it could work for you -

G string - Thumb
C string - Thumb
E string - Pointer
A string - Pointer or Middle finger

I find my thumb too slow for this to work well but it might be just right for you.

Let me know what works if anything of the above, I'd love to know if what I said worked for someone else and also what didn't really fit.
That video was interesting even though Yousician hasn't introduced hammer ons and pull offs yet. I've tried them on my own prior because some songs I found online used them. A lot of sources just assume you already know how to do them and do what that video did and show you what to practice or something, but not how to do it. In the last day or so, however, I've been on a major rabbit hole via Wikipedia and the wider internet learning about picking in its various forms and feel like I have a somewhat better grasp now. I even found a video which actually explained pull-offs. (I'd been attempting them wrong, so of course they weren't working.) I'll take a look at the Youtubers you mentioned, too.

As for positioning, I think I'm going to have to keep experimenting. It's hard to alternate pick and support the uke, at least the ways I've tried. I've been tempted to get a strap, but my uke doesn't have a place to attach it on the bottom and I'm not *quite* ready to drill a hole in it to install a strap pin, yet... :-)

As for the fingerpicking styles you mention, I've used the thumb/index/middle/ring one a bit, but I have more experience with the thumb/thumb/index/middle mostly because Yousician told me to use that one.

As for being more comfortable with using my thumb? Yousician didn't even introduce any alternatives until very recently in my progress, so I've definitely had the most practice with it. Since I'm still finding it hard to get better at alternate picking using the songs Yousician is supplying to practice with, I went back to the previous levels and started playing them with alternate picking. This seems to be helping. I still have a ways to go, but practicing on the easier and slower songs means that I'm not totally failing when both hands try to do something hard. I figure if I keep going through the old songs and get alternate picking to be second nature, then the faster songs are going to be a lot easier to learn. I guess we'll see.

Thanks for the advice and recommendations!
Changes to songs??

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