banjo - damryjgita (any stringed instrument with a drumskin soundboard)
violin, specifically - violni It seems inconsistent to have a fu'ivla for violin specifically but not guitar.
Music Theory
algorithmic music - pruce zgike? tadji zgike?
chord - togygri?
$g_1=t_1 are a group of tones of frequencies/pitches $t_2 showing common property (such as scale membership) (ka) $g_2 showing tonal relation $g_4
counterpoint -
harmony - togygri saske?
intonation (as in playing in tune or not) - tonga srera klani?