Hello! If u want to say "I was a musician" you should say "я был музыкантом " so, if u want to say who u were you should say "я был ...."for example: я был учеником, учителем..... if u want to say "I'll be a musician" u should say: "я буду музыкантом " so u say "я буду ... " for example я буду учителем, писателем... Good luck)

ясно, понятно. и еще... "what does it mean?"

Uzbekistan)