My 9 year old son is doing really great on bass and is ready to move to full-size. He's been playing 3/4 so far. His teacher suggested we move to 6-string right away, without spending a few more years on 4 or 5 strings. So we need to find a suitable bass. We would like it to be light and sound is of course important. Short neck would probably help, but we tried Ibanez BTB and the kid could play it. I'd appreciate some recommendations on basses we should try out. The kid plays everything from rock to funk to jazz. So the bass needs to be versatile. Thanks for your help.