A musical instruments is an instrument that can make musical sounds, it can be a traditional instrument created specifically to make music or something adapted to play music.

432 Hz is Better than 440 Hz Myth

It’s theorized that using a starting pitch of A=432 Hz and a “just intonation” tuning method (scientific tuning) is more natural and mathematically symmetric than using A=440 Hz and “equal temperament” tuning (concert tuning).

A Synthesizer Always Has a Keyboard Myth

A synthesizer is an instrument that uses electronics to produce sound. Sounds produced by a synthesizer are commonly triggered by a keyboard, but not always.