The D-50 introduced LA Synthesis (linear arithmetic), which is a method of synthesis that combines ROM samples of attack and sustain waveforms in order to build instrument sounds. Sounds are built using four tones, two "upper tones" and two "lower tones".
The PG-1000 editor can be used to make patch editing easier. Patches can be saved to an M-256D or M-256E RAM card and its patch memories are maintained with a standard CR2032 lithium battery.
The D-50 is monotimbral but can be expanded to 8-part multitimbral with the M.EX multimode expansion (which also adds 192 patch memories). Roland also released a series of 4 memory cards (PN-D50-01 through PN-D50-04) containing patches but no additional sound waveforms. Eye and I Productions has also produced six Voice Crystal expansion cards for the Roland D-50.