One of the things I believe makes a 'complete' musician is his (or her!) ears...

The ability to just hear something, and know how to play it, or to play something that fits is the primary attribute of a complete musician. "Big ears' is one of the most welcome compliments any musician can get. Yes, reading can be important at SOME gigs (fewer and fewer these days!), but a well honed set of ears is FAR more important. They are the foundation for everything you do.

Technology is useless without them. Singing is futile without them. Musical growth, impossible.

I feel that rigorous ear training is the most important thing you will ever get to do to improve your chances of a long and happy relationship with music. Interval recognition, chord recognition, melody memorization, these are basic skills that few music programs give the importance they deserve. A half hour a day at JUST this, and in a year you will not recognize your own playing!

If your ears are sharp, as long as you can play a chromatic scale on ANY instrument, you can play it on a gig. The rest is just ears..! Hearing music in your head, and IMMEDIATELY being able to play it on whatever is in your hands is the goal of any musician.

Technology knowledge is useful, but ALL of us can probably remember a time we heard some guy on a beat up old DX7 or an ancient arranger just totally tearing it up! Connecting the music in your soul with whatever you have at hand is far more important than knowing element structure in a Motif, or how to use a T2 sampler...

And, yes, Russ is right... There is no such thing as a complete musician, just dedicated players continually trying to improve, knowing they will never know it all...