Oboe.
An organ is a solid musical instrument. It begins with the letter o.
One such would be the ocarina, also known as the sweet potato.
A musical instrument would be the jug. It begins with the letter J.
Glockenspiel
ukulele
Ukulele
mandolin
kazoo
Ukulele
No, there is not a continent that begins with the letter O.
Recorder is a musical instrument. It begins with the letter r.