This is a montage of three numbers from what looks to be (from all the videos of it I've seen) a superb concert version that the Encores! group put on of Fiorello! in 2013 at the New York City Center. It was the start of the 20th year of the Encores! series, which had begun two decades earlier by putting on, as its inaugural show...Fiorello! This was the first time they'd ever repeated a musical.
In this montage, we see extended version of three songs during rehearsals. Shuler Hensley plays 'Ben Marino,' Kate Baldwin is 'Thea' (and we see a bit of Danny Rutigliano as 'Fiorello'), and then Erin Dilly plays 'Marie.'
If Erin Dilly looks familiar, that may be because of his role in the film, Julie and Julia. She played to book editor tasked with testing the recipes in Julia Child's cookbook and then sitting down with the co-author and coming up with a title. Kate Baldwin recently starred on Broadway in a revival of Finian's Rainbow, and Shuler Hensley played Jud Fry in a 2002 Broadway revival of Oklahoma! -- fascinatingly the role created by Howard DaSilva, who also created the role of 'Ben Marino' that Hensley played in Fiorello! He also was in the recent musical version of Mel Brooks' Young Frankenstein as the Creature. I don't know all that much about Danny Rutigliano, alas, but he's wonderful in the videos of the show, and was in the original Broadway cast of The Lion King, as Timon, the role voiced in the animated film by Nathan Lane.
But now, on to the montage. A robust "Politics and Poker," a gorgeous "'Til Tomorrow" and an energetic "The Very Next Man" with the new "When he proposes..." lyric.