I've been playing bass for like 6 or 7 years now. No lessons, I can't read music, I don't know any scales although I've been half assed learning here and there. I started out learning some songs from bands that I liked. I'd find tabs online or whatever and just play along until my hands felt like fire.
The first band I was in was a hardcore/metal band. I've never had problems communicating with other band members. Although our way of telling each other what to play wasn't "proper" it worked. Someone would make a part, play it slow for everyone else until it stuck. Then we'd start trying it at the right speed. If they where playing a wrong note in the riff or whatever you'd say something like, "no play a 6 on the A string". It may not be proper but it gets the job done. I played with my fingers where most bands of the style use picks. I used chords here and there in that band which is not something common for a bass player in that genre to do. I always got compliments for it though. But I also knew enough to know not to over use chords and I've always understood that sometimes "less is more".
I'm currently not playing bass in a band, but I do sing (scream/yell) for one. We all take part in writing pretty much. It's been mostly our one guitarist but the past couple songs started with riffs I made and another recent song started with a riff our drummer wrote. For the past few years now, a large chunk of the music I listen to is hardcore/punk/noise type stuff (Converge, Botch, Coalesce). Lots of dirty heavy music. We play stuff that's fairly close to that. I can't make those kind of songs on bass though. Maybe a part here and there but most of the time when I have some part in my head, I go to a guitar to work it out because I can hear it clearer on a guitar than bass. When I'm writing something I just start to work out the riff I hear in my head, change notes in it and all that stuff and change the rhythm of it until I think it sounds good. I take into consideration my bands existing songs so I don't make something that sounds like something we already have. Then I bring it to practice, and if they like it I then show them how to play the part, or song.
I still use chords when I'm just screwing around. I couldn't tell you what the chords are named, but I could tell you to form them by playing for example A8, D7, and G9 or playing A12, D14, G16 etc...I just figured out what chords sound good to me and what doesn't. I can make stuff like Tool songs that are played on the D and G strings, and I can also turn on Ol' Dirty Bastard the Third (ODB3), crank the gain and pummel my eardrums with some sludgy hardcore riff. I play mostly with a pick now and I think I have great control. I only play hard when I need to. I can play with my fingers fairly well, I can do slap pretty good. I can do a few two hand tap things but nothing spectacular. All without a single lesson. Whenever I want to learn something new, I can usually find it online. For the music I make, I know everything I need to know so I'm happy with that.
Like someone else said, some genres you will be set just being self taught, some genres depend on knowledge of theory and scales and all that stuff. Your friend should figure out what he might want to do on bass, learn some songs that are in that style. I think that's a pretty damn good way to start.
There's my two cents anyways... well maybe more like a dollar.
The first band I was in was a hardcore/metal band. I've never had problems communicating with other band members. Although our way of telling each other what to play wasn't "proper" it worked. Someone would make a part, play it slow for everyone else until it stuck. Then we'd start trying it at the right speed. If they where playing a wrong note in the riff or whatever you'd say something like, "no play a 6 on the A string". It may not be proper but it gets the job done. I played with my fingers where most bands of the style use picks. I used chords here and there in that band which is not something common for a bass player in that genre to do. I always got compliments for it though. But I also knew enough to know not to over use chords and I've always understood that sometimes "less is more".
I'm currently not playing bass in a band, but I do sing (scream/yell) for one. We all take part in writing pretty much. It's been mostly our one guitarist but the past couple songs started with riffs I made and another recent song started with a riff our drummer wrote. For the past few years now, a large chunk of the music I listen to is hardcore/punk/noise type stuff (Converge, Botch, Coalesce). Lots of dirty heavy music. We play stuff that's fairly close to that. I can't make those kind of songs on bass though. Maybe a part here and there but most of the time when I have some part in my head, I go to a guitar to work it out because I can hear it clearer on a guitar than bass. When I'm writing something I just start to work out the riff I hear in my head, change notes in it and all that stuff and change the rhythm of it until I think it sounds good. I take into consideration my bands existing songs so I don't make something that sounds like something we already have. Then I bring it to practice, and if they like it I then show them how to play the part, or song.
I still use chords when I'm just screwing around. I couldn't tell you what the chords are named, but I could tell you to form them by playing for example A8, D7, and G9 or playing A12, D14, G16 etc...I just figured out what chords sound good to me and what doesn't. I can make stuff like Tool songs that are played on the D and G strings, and I can also turn on Ol' Dirty Bastard the Third (ODB3), crank the gain and pummel my eardrums with some sludgy hardcore riff. I play mostly with a pick now and I think I have great control. I only play hard when I need to. I can play with my fingers fairly well, I can do slap pretty good. I can do a few two hand tap things but nothing spectacular. All without a single lesson. Whenever I want to learn something new, I can usually find it online. For the music I make, I know everything I need to know so I'm happy with that.
Like someone else said, some genres you will be set just being self taught, some genres depend on knowledge of theory and scales and all that stuff. Your friend should figure out what he might want to do on bass, learn some songs that are in that style. I think that's a pretty damn good way to start.
There's my two cents anyways... well maybe more like a dollar.

