Guitars

[GorDon]

I need to know Animes where are music bands or Guitars. Like K-ON, Detroit Metal City, Nana, Beck etc. Thaks VM

[Kariudo]

you'll find some of that in...
Android Kikaider (guitar)
Bubblegum Crisis Tokyo 2040 (band)
Haruhi
Trigun (Jazz band)

...and that's all I can think of off the top of my head that isn't stuff like Nodame Cantabile

[8bit_samurai]

Here's another thread with a list of guitars. Can't really think of anything that isn't already mentioned, though.

[Ishbalan]

Excel Saga comes to mind.

[Vivaldi]

I need to know Animes where are music bands or Guitars. Like K-ON, Detroit Metal City, Nana, Beck etc. Thaks VM

BECK: Mongolian Chop Squad

[Flame-X]

Kaikan Phrase

[seasons]

If you see anything here that you like, then go to Interstella 5555.

[Knowname]

Black Heaven FTW!

[AaronAMV]

FLCL

[Willen]

The thread 8bit_samurai linked to has most of the major ones.

School Rumble season 2 has some in the early episodes.

I'm fairly sure there were some scenes in Shugo Chara during the earlier Utau episodes.

And this is probably not what you are looking for, but there's the little bit in Whisper of the Heart where Shizuku sings "Country Road" accompanied by Seiji, and later, with Grandpa and his friends.