The Rhodes Piano Bass is a unique keyboard that only has two octaves of bass notes. There are a few different versions of the Piano Bass, but I don't think that all too many of them were made in general. It became a well known instrument because of it's use by The Door's keyboard player/bass player, Ray Manzarek. I don't know if he used this all the time or not, but it's definitely got that fat bass keyboard sound that made him famous. I don't think that there is any difference between this and the lower two octaves of a regular Fender Rhodes, but nonetheless it's cool how compact this keyboard is. Since it only spans two octaves and no real tone controls, there isn't much versatility at all here, but what the Rhodes Piano Bass is good it, it's the best of it's kind. The feel of the keyboard is pretty much the same as a normal Rhodes, as the action is easy to play and light without feeling cheap at all. Pretty much everyone has heard the sound that the Piano Bass has in some capacity or another, which can be described as better really round, fat, and juicy. It's probably the best sounding bass that I've heard come out of a keyboard, as it's so smooth and rich sounding. I think that you could find one of these used somewhat easily if you were willing to spend some money, although I'm not sure exactly what kind of price these do command. My thinking would be that they would be cheaper since they are smaller than a regular Rhodes, but at the same time these are definitely a lot rarer than your typical Rhodes. So if you're interested in the Fender Rhodes sound, I'd recommend going with a full keyboard first, but if you're looking to add to your collection of keyboard, the Rhodes Bass Piano is an awesome instrument to have around.