If you are a guitar player, I highly recommend that you don't wait as long as I did to get yourself a bass.
Why? Because the approach and technique are so different and yet we sort of know this instrument already, don't we?
They are our bottom four strings! You already know where the notes are, but now you are laying the foundation, the underpinnings, the lines that lead in and out of versus and choruses.
Most of all, it's just plain old fun to play. Don't wait!

