With an acoustic guitar, the lyrics are often easier to make out than they would be with an electric guitar. The words that accompany the music thus take on greater significance. And when words are important, the spelling of them follows. Have you ever tried to look up lyrics on the web and found them riddled with typos? Or originally misheard them and then always thought, for example, that Jimi Hendrix was saying, "Excuse me while I kiss this guy"? These musical misapprehensions are known as mondegreens (a confusion of "Lady Mondegreen" for "laid him on the green"). There are 54 samples of Accoustic* in OhioLINK, but that middle C is a clam.
(Clam City Ramblers from the CCR website.)