If you only sing and don't know anything about music or do not play any kind of instrument, you're a vocalist.
Just wondering.. Those that sing in the shower.. Are they considered vocalists also??
Imo humbly so, a trained vocalists (a singer in the case deb might be refering to) requires in depth knowledge of music, articulation and timing and extensive vocal training such to refining how to master ones instrument. And such would have rightly obtain their title as a musician.
Heh, I didn't think I'd join this discussion, but you're on the right track, Kytrinh. My aunt was a soprano with the The Royal Opera House Covent Garden. To be so, means lifelong, ongoing training, with annual auditions to see if you're on top of the task. An operatically trained voice goes places I, and probably most others on here, can only imagine. Plus you need to be able to sightread classical scores. Now, there should be little doubt as to whether or not the voice is an instrument and that the possessor of such an instrument is very much a musician.