"" O
"" Ob.
"" Obbligato
"" obbligatorio
"" Ober
"" obligat
"" obligatoire
"" obligatory
"" Obligé
"" Oblique motion
"" oboe
"" Oboe d'amore
"" Oboe da caccia
"" Ocarina
"" Octatonic Scale
"" octave
"" Octave bass clef
"" Octave clef
"" Octave designation
"" Octave treble clef
"" Octavo
"" Octet
"" Octuple croche
"" Ode
"" Oeuvre
"" Off-beat
"" Offertory
"" Office
"" Officer's Call
"" Ohne
"" Ohne Dämpfer
"" Ohne Instrumente
"" Oktave
"" Oktavflöte
"" Oktavierende Schlüssel
"" Old Roman Chant
"" Old-time music
"" Oliphant
"" Ondes Martenot
"" One hundred and twenty-eighth note
"" One hundred and twenty-eighth rest
"" One-line
"" Op.
"" Open
"" Open fifth
"" Open form
"" Open roll
"" Opera
"" Opéra bouffe
"" Opera buffa
"" Opera comica
"" Opéra comique
"" Opera seria
"" Opera-ballet
"" Operetta
"" Ophicleide
"" Opp.
"" Opus
"" Oral tradition
"" Oratorio
"" Orchestra
"" Orchestra bells
"" Orchestration
"" Ordinary
"" Organ
"" Organ point
"" Organ verset
"" Organal style
"" Organistrum
"" Organology
"" Organum
"" Ornament
"" Ornamentation
"" Orpharion
"" Ossia
"" Ostinato
"" ottava
"" ottava bassa
"" ottava rima
"" ottavino
"" Ottoni
"" ouïe
"" Outer voices
"" Ouvert
"" Oval
"" Overblowing
"" Overstrung
"" Overtone
"" Overture