"Subspace Rhapsody" is an episode that you either love or hate. Me? I loved it.
In this trifle of a song, Captain Marie Batel calls Captain Christopher Pike to complain about the cancelling of their planned vacation. Unfortunately for them both, they are under the effect of a quantum uncertainty field that causes them to break out into song. Even more unfortunately, this happens on the bridge of Enterprise in front of the entire crew.
Neither Anson Mount nor Melanie Scrofano are the strongest singers, but that doesn't matter. What plays out is an amusing little back and forth argument that culminates in Pike collapsing to his knees in a full-on stage performance that is cut short when La'an mercifully closes the channel.
I have to also compliment Anson Mount here for absolutely giving his all to his performance here. I've appreciated the multiple times now where he's been unafraid to make himself look a bit ridiculous in service of the story (see also his sniveling coward performance as Sir Rauth in "The Elysian Kingdom.").