It's important to note, though, that learning to sing while playing will make you exponentially more valuable in any band situation. I contract a lot of musicians for paying gigs and I would take an adequate bass player who sings over a monster bass player who doesn't every single time. Matter of fact, from my perspective (as someone who writes checks to musicians), if you don't sing, why even bother playing bass? Because there are guys who do sing and they'll always get the gig over you. Amazing instrumentalists have a very, very limited appeal- mostly to other amazing instrumentalists.QUOTE]
This is absolutely true. I know 3 or 4 session bassists that can play circles around me. They can solo over anything and you simply cannot stump them. But not one of them sings. We have a group of musicians we all know and they do a wide variety of gigs, hiring players as needed. I get WAY more of those gigs than the session guys do, and it's because I can contribute to the vocals.
I would consider myself a very solid bassist, but I'm a groove player, not into solos or flashy playing at all. BUT, I have a strong tenor voice, I can sing lead or backup, and I have enough theory command to be a harmony machine for other singers, i.e. they can sing songs I don't even know and I'm able to jump in with a harmony part that works.
That will really expand your options as a gigging musician.
The other posts here about learning the bassline so well it's automatic...that works for me. And after you do it long enough you will be able to do it on demand, i.e. with songs you don't even know. It's just another skill that comes with lots of practice.