The Flash (The CW, 8 p.m.): The combined casts of Supergirl and The Flash are packed with singers, boasting alums from Glee, Rent, and, uh, Smash. (Sorry, Jeremy Jordan, we know you have other credits and the voice of angel.) This makes tonight’s crossover episode seem both exciting and inevitable. “Duet” finds Kara and Barry besieged by the Music Meister (Darren Criss, another Glee vet), who robs them of their powers and forces them to live out a musical. As they get out of this pickle they’ll sing original tunes by Crazy Ex-Girlfriend’s Rachel Bloom and Oscar-winning La La Land lyricists Justin Paul and Benj Pasek. Scott Von Doviak will weigh in on the extravaganza.
Dave Chappelle: Deep In The Heart Of Texas and Dave Chappelle: The Age Of Spin (Netflix, 3:01 a.m.): It’s Dave Chappelle day on Netflix, with the streaming service debuting two separate specials from the comedian, his first in more than 10 years.