I've just started learning Scott Joplin's "The Entertainer", and I think my edition must have a misprint. I'm hoping someone can double-check and confirm my suspicion.
In measure 18, in the left hand, on the second beat, the sheet music shows an A♭ octave followed by a chord spelled G-C-F (see the photo). That chord has an open-fourth sound which sounds out of place in Joplin's music. I figure the bottom G's gotta be an A♭, making the chord an F-minor inversion. Can anyone confirm? Or is the printed music, in fact, correct?