[FredZarguna]

Not a grammatical or punctuational insult. Even well acquainted with the legend of Robert Johnson I simply had, [and still have] no idea what this phrase means: "with an baking out of tune acoustic trowed."

[Eddie01]

Bakin* implies heat. Heat refers to something that is... hot.

Out of tune signifies the heat’s impact on the guitar’s tuning.

Acoustic is the the non-electric guitar and style of Robert Johnon.

Throwed over his shoulder is vernacular for Thrown over the shoulder. A typical drifter trait of the loathsome guitar player of the times.