-Bass players who ask to try out my fretless, then try to slap the hell out of it.
+1
"oh maaan, you can't slap on a fretless!" -Guitar player who happens to know how to slap on bass as he feebly tries.
-Happened to me once, should have left the band right there in retrospect. Volume during rehearsal is on .75 (granted, the gain was at 6, my mistake, but the bass frequencies were completely cut out), lead guitar player said, "Turn that down! The neighbors can hear it," turn it down to zero, the guitarist says, "That's better," no joke, no fooling around, he thought nothing was an ideal volume coming from me. Now... why was I present? Then again, hindsight is 20/20.
[Both happened at the same rehearsal]
-the preconceived notion that a bassist is nothing more than a disgruntled guitarist, and a drummer is nothing more than a very disgruntled guitarist.
-the preconceived definition that a good bassist exclusively means you can slap, and because you can slap exclusively means you're a good bassist.
-guitarists taking the spotlight couldn't be a more acceptible thing in my book. When they can't leave the spotlight, that's when I become irked. I was playing trumpet in a jam band awhile back, guitar player was soloing, I took a solo, guitarist was STILL soloing, drummer took a solo, guitarist was STILL soloing, the bassist, I, and the drummer fell back in the pocket going out, and the guitarist was STILL soloing.
-Same guitarist as directly above, admired Jaco's bass playing, saw my fretless bass, immediately took it, started playing slides on it, then proceeded to dig the strings as hard as he could into the fretboard and perform a guitar vibrato. I pointed out that he would prematurely wear out the fretboard, and he responded, "So what? Jaco did that!" Hmm, don't recall Jaco doing that (could be wrong), but the lack of respect he had for my own property really got me irked.