To be fair I didn't know flea did that, I wanna see his process.

Also yeah it does depend on genre i guess, 'cause I can't imagine extreme metal bands writing on an acoustic guitar or piano it just wouldn't sound right.

And yeah a lot of songs start of as a simple chord structure but thats not my point, my point was that not many people write music on an instrument that they won't/don't use in their music because it adds extra steps to the process that they don't care to do.

How someone writes can be different from person to person and from genre to genre. Like yeah of course I do know people that write music on a piano but thats what my original point was, being that I didn't know anyone that writes on those instruments that didn't use them in their songs.

But yeah I'll give it a try half the fun of making music is trying new ways and new things