I have noticed that picks that are generally marketed towards mandolin players are rounded. Is there any reason for this? Is it a tonal thing? I have always found rounded picks to be more difficult to play fast with. I’m guessing if they were easier to play fast with then a lot of shredders would use them.
Any ideas?
You’re teeing this one up for us, right? 
After we released the mega compendium of pick tests a couple years back, we then took that and boiled the most important points all down to a single video aimed at not overwhelming beginners. It’s called “The Rule of Roundess”:
TLDR acoustic instrument players are going for a bright sound that projects but still has bass. A heavy gauge rounded pick played with a lower (i.e. flatter) amount of edge picking achieves this. The amount of edge picking depends on the instrument.
On mando, because it’s already a smaller more treble-focused instrument, you can use a pick like this with a little edge picking and still get a balanced sound. But on a guitar you’d have to play the pick you’ve pictured almost totally flat, like David Grier. With edge picking, a rounded pick gets super dark real fast, and it’s hard to hear anything.
You might ask, why not use a pointed pick with lots of edge picking? You can! On acoustic, you can almost get a passable sound out of a jazz III played with high edge picking, though it will take a beating. Some classical mandolin players use super pointy quill-style picks played with high edge picking. They get a super-aggressive bright sound.
But in bluegrass, more of a balance between bass and treble seems to be the signature sound, and a heavy gauge rounded pick (played flatter on guitar) is the loudest option that gets the closest to that.
Thanks Troy - to be honest I hadn’t watched that video 
That’s fascinating and now makes a lot of sense now that it’s been pointed out.
I don’t really know of any rock players who use a more round pick, although Frank Gambale uses the large triangle type. I’m guessing this is generally because the thicker picks don’t give enough high-end attack for when using high gain type sounds?
Right, I think it’s a Goldilocks-tyle situation where none of the combinations really fit. If you have a super round pick, especially at a heavy gauge, and you try to play it with a higher amount of edge picking, the sound is going to be dark. But more so, you’ll also be sliding right off the string. It’s hard to get any grip with a rounded pick played on edge. So you take that same pick and play it flat, and now it’s very bright — maybe too bright.
So rock tends to gravitate toward pointier picks with more edge picking. Bluegrass and acoustic styles in general gravitate toward rounder heavier picks played flatter. But just like the Jazz III bluegrass test, I’m sure we could find less common combinations for rock that work for certain mechanical approaches / musical styles and amp tones. Gambale probably being a good example of that. The Planet Waves celluloid pick he used in our interview is 1mm, so not super heavy. I’m not sure if we mention it in the roundess lesson, but we talk about in the 346 overview here:
Oh, one other thing with a lot of these round picks is chirp. They’re usually harder material and heavier gauge i.e. way more massive than thinner picks. If you try this on an amped electric guitar there can be an almost comical amount of chirp, like a mouse squeaking on every note:
Troy, thanks again for your input and explanations.
Ah! This might be the reason I didn’t like the sound of ultex jazz III I recently tried. High degree edge picking, hard material and a sound that I just remember thinking was… odd. I’ll give them a try again tomorrow and see if it was the chirp that was bothering me.
If H is the “penetration depth” that one wants for the pick into the plane of the strings, rounded points, flexible plastic, and edge picking are three “safety blankets” to protect against the mistake of going deeper than intended.
My pick (Dunlop Flow) looks like a point for low penetration depth but if I go too deep the broad shoulders make it look smooth, and I think this behavior is by design.
CtC has shown that there is tremendous diversity in the guitar world (for good and bad), and some people just want to skim that string (Rusty Cooley comes to mind).
