Who kidnapped Sally Rogers?
Randy Bowers rides into town, and upon hearing a grossly off-key rendition of "Sobre las Olas" coming from a saloon, enters to investigate. He walks in to find the patrons and bartender all shot dead, with the song coming from a player piano, along with a note advising the local sheriffs not to investigate. The sheriffs arrive and immediately blame Randy for the massacre. Within the sheriff's posse is Matt the Mute, who cannot speak and writes to communicate—using the same handwriting as was found in the note.
Randy escapes with the help of Sally Rogers, the niece of the dead owner of the bar, who survived the massacre by hiding in a crawlspace. Randy runs from the sheriff and ends up in a cave in which the bandits have their hideout. They kidnap Sally, who escapes with Randy's help. Matt the Mute is eventually exposed as the real killer and is himself killed when he enters the bar, which is filled with explosives. 
In the end, Randy and Sally are married, and they live happily ever after.
the bandits