Stumbo and Steady Eddie gave great advice. Lots of other good advice too. But to train your ear, you must have an ear. You have to be able to hear a note and then play that same note on your bass.
For me, what worked was choosing a few songs in the same key - so that the same notes would come up and it was more like a multiple choice test than an open-ended qui all the time. It came naturally to me, somehow, to be able to hear and match the open strings (and then of course, use different positions to play the same notes). Little by little, a person learns to find the notes in between - some people have such a good ear they really only have to hear a line once or twice and they've got it.
It's related, of course, to learning theory because, if you don't have a great ear, you'll be using logic and theory to deduce what the notes may be. It's not as if most bass lines contain random notes.
I agree that singing is really helpful - something I learned here on TalkBass, and which definitely has helped my bass playing more than I would have ever thought it could. Sing those bass lines, sing the melody, but learn to sing the bass lines (there are bass lines in symphonies, church music, and learning to find and sing them is a lot of fun).
For me, what worked was choosing a few songs in the same key - so that the same notes would come up and it was more like a multiple choice test than an open-ended qui all the time. It came naturally to me, somehow, to be able to hear and match the open strings (and then of course, use different positions to play the same notes). Little by little, a person learns to find the notes in between - some people have such a good ear they really only have to hear a line once or twice and they've got it.
It's related, of course, to learning theory because, if you don't have a great ear, you'll be using logic and theory to deduce what the notes may be. It's not as if most bass lines contain random notes.
I agree that singing is really helpful - something I learned here on TalkBass, and which definitely has helped my bass playing more than I would have ever thought it could. Sing those bass lines, sing the melody, but learn to sing the bass lines (there are bass lines in symphonies, church music, and learning to find and sing them is a lot of fun).

