aA bA cA dA eA fA gA hA iA jA kA lA mA nA oA pA qA rA sA tA uA vA wA xA yA zA [ C/U ]   music   plural A’s or As in Western songs, the sixth Observe in the dimensions (= series of notes) that begins around the Observe C, or perhaps a list of notes determined by this note ⟨