Pro Tools' included instruments run the gamut from sample playback (Xpand!2 and Structure Free) to synthesis (Vacuum) to drum machine (Boom). There are also two classic instrument simulations'"grand piano and Hammond organ. I'll be taking a look at the latter, the DB-33 Hammond organ plug-in.
Real Hammond organ & Leslie cabinet
The Hammond organ is one of the classic electronic (actually electro-mechanical) instruments of the modern era. Dating all the way back to the 1930s, it was originally intended as a replacement for the traditional pipe organ, but found its own voice in gospel, rock, and R&B music, from the '50s and '60s up through the present day. The original utilized mechanical tonewheels to create the sine waves which form the basics of the additive synthesis tones that all organs use to build up a rich sound. Up to nine tonewheel-generated harmonics can be combined for each note played'"a total of 91, including an extra to provide an optional percussive 'plunk'