Turn your Nord Drum 2 or 3p into a 6 voice polyphonic synth where the note length depends on how long you depress a key.
On your ND2 or 3p program the SAME sound on all 6 drum channels: use pitch=60 for all, and the longest tone and noise decay possible (you may want to try linear decay). In MIDI settings engage the Individual MIDI channels 1-6; that is: MIDI channel 1 for drum channel 1, 2 for 2 etc..