willow

Most of the ones I can think of have girls as main characters but aren't sufficiently girl centric like Nodame Cantabile and Kono Oto Tamrare!
Never actually watched it but I've heard good things about Nana
e: found another one I was thinking of, Kuuden Noise no Himegimi

The rhythm game Unbeatable is about 3 girls (and 1 boy) in a band together. It's not out yet but there's a demo they've slowly been adding to over the past couple years and they've done crossovers with a few other indie rhythm games. The Spider-Gwen comics also come to mind (along with the opening scene of Across the Spider-Verse) although the band is obviously very much not the focus and Gwen is constantly flaking on them.

The Runaways is alright; not amazing but it's got some fun performances. I've not seen it but I've heard good things about We Are The Best; there's also Kids on the Slope (manga and anime both) which isn't girl band focused but has a lot of good band practice dynamics stuff in it

Hello Melancholic is a 3-volume yuri manga about girls in a band that I like quite a bit!

I've been playing a lot of Project Sekai lately if "gacha rhythm game" is specifically a format you enjoy; only one of the 5 main groups is actually a girls band with instruments, but you can easily ignore the others.

Whisper Me a Love Song bears mentioning because it's 100% a (yuri) girls band manga, but it's not a personal fave.

I'll also second Nana bc it's my current obsession--there's really only a couple of featured Band Girls, both primarily singers, but music and women's relationships with each other are absolutely central to the plot.

• Lisa Simpson in the intro plays sax in a band (sorry)
• The Hex Girls from Scooby Doo
• Amythest plays drums and Pearl plays bass for Mr Universe and Roze Quartz in a flashback
• Sadie Killer and the Suspects has Jenny Pizza on guitar
• Marceline
• Pearl on Sax and Sandy on Guitar for Sweet Victory from SpongeBob

Show by Rock is a fantasy idol-type show but it's all framed as various battle of the bands, with them playing instruments and everything. Most are pop-to-pop-rock-y but it may still count? Mostly girl bands but some guy ones thrown in.

okay so I can't actually recommend Macross 7 BUT Macross 7 is about a girl who plays bass in a rock band, who eventually ends up fighting aliens by playing rock at them, while piloting a mech. The controller for operating the mech is a bass

this is, obviously, the coolest fucking premise ever written. Unfortunately they made it suck, somehow (largely by focusing most of the plot on two incredibly shitty and boring boys instead of the unbelievably cool girl protagonist)

rather than actually watching Macross 7, I recommend looking at these screenshots of the main girl's insanely powerful 90s fashion outfits

you will love the webcomic Band Vs Band

do you want good media or just any media? We Are The Best! definitely counts but I didn't think all that much of it

I only saw half of We Are The Best! but it seemed pretty cool.

We Are Lady Parts!

How do we Relationship is partly about girls (and guys) in a band, but is mostly about messy lesbian relationship in college

If band makeup of nonbinary, girl and guy would count then I’d recommend Goodbye Volcano High!
They’re dinosaurs but the story focuses around the band and their performances. Also the music slaps.

I know you said you've seen/read Bocchi, but did you know there is a spinoff starting Kikuri and her band?

It's called Bocchi the Rock! Gaiden: Hiroi Kikuri no Fukazake Nikki. It's mostly about Kikuri's drunken antics between gigs, but you do see a bit of her playing sometimes. Comedic overall, but with enough sprinklings of sadness to keep you rooting for her.