solid body electric guitars (3)
acoustic electric guitar (1)
acoustic guitars (5)
mandolin (1)
Irish bouzouki (1)
chromatic harmonica (1)
harmonicas (2)
piano (1)
violins (2)
unassembled dulcimer (1) (its only been 10 years, but I'm patient)
guitars disassembled or injured (3)
pitch pipe (1)
tuning fork (1)

Of these, the only one considered mastered is the tuning fork.