The loom 'harp'
That can't have been a functioning harp, but it sure as heck looks like Harpos' playing it. How did they do that?
shareI expect (correct me if I'm wrong) the musical numbers were pre-recorded, then mimed for the camera. That way they can cut between takes without audio issues (different takes in different tempi, etc). They probably just took advantage of that by letting Harpo mime on a loom.
I thought it was a beautiful piece of music, by the way. But then Harpo's performances always are. Such a contrast to the anarchic comedy, but it fits perfectly.
I perferred the earlier films where Harpo and Chico, and Groucho, too, performed live in front of the camera rather the later films where they mimed to a prerecorded performance. The live performance may not have sounded perfect, but they were live, and it felt more spontaneous.
shareIt was obviously dubbed later, since a real harp has (and needs!) pedals. No pedals in sight here. (Since all the "flash" goes into watching the strings, it's easy to miss the pedals, but they're there on a harp, trust me. Go back and look at some of the other films...which is as good a reason as any to drag them all out again! lol)
On the other hand, I would assume that it really was a recording of Harpo, and he's syncing his playing exactly as originally performed.
(And before anyone gets "technical" on me, I'll grant that it's conceivable to write a harp solo whereby the pedals are never used...but I doubt very much that that was the case here.)