We’ve spent the interim between seasons one and two of “Schmigadoon!” catching up on some of the musicals referenced in the wild song-filled comedy series (note to everyone: “Carousel” is a trip that might scar you forever), so we’re ready for the next round. The second season will follow stars Cecily Strong and Keegan-Michael Key as they enter the world of “Schmicago” with a storyline that will no doubt be steeped in famous musicals of the ’50s, ’60s and ’70s. The regulars this time around will include song-and-dance man Tituss Burgess (“Unbreakable Kimmy Schmidt”), Broadway regular Patrick Page and a variety of other special guest stars. Musical theater kids, gets ready for the April 7 drop on Apple TV+ for an ongoing game of “Spot the Obscure Reference.”