I have a Panama Canal cruise on Eurodam on March 14th and my itinerary/events schedule is showing music in BB Kings Blues Club, Lincoln Center Stage, Billboard Onboard and the Main Stage.
There appears to be more than enough musical events.
Lincoln Center Stage events listed are Masterworks by Mozart, La Musica Latina, All American, French Connection, The British Isles, Just the Strings, Music Around the World, Masterworks by Brahms, A Night at the Ballet and last but not least, Meet the Artists of Lincoln Center Stage.
I've never been on a HAL cruise but that sounds like a nice array of musical events throughout the music row area