This is in response to something I posted on that since when can any guitarist play bass thread, that was closed. I think this is worth saying though. The "traditional" role of bass is to provide the lowest melodic voice. Bass is no more a "rhythm" instrument than any other instrument. Guitar is just as much a rhythmic instrument as bass, for example, and bass is no more like drums than guitar is, really. While drums are also tonal and technically melodic instruments they are not strictly subject to chromatic tonality in the sense that bass and guitar generally are, microtonal instruments aside. In fact if anything bass is more akin to the left hand playing piano. With that said, in certain circumstances bass is treated in a more or less "percussive" way, but it is also treated in a more or less melodic or harmonic way. In my opinion the assertion that bass is part of the "rhythm section" is just another limitation.