In Impulse Tracker if you copy (Ctrl+C in modplug) a template of several rows and/or several tracks like say :
|C-401......|F-403......|G-403......|D-503......
|...........|...........|...........|...........
|...........|D#403v20...|...........|...........
|...........|...........|D-403v20...|C-503v20...
You can then go into template mode with Alt+I : then every note you enter replicates the same template with all the notes lifted (the first note of the first track acting as reference).
All the notes are also played simultaneously (maybe just for the first row though).
Here, just entering the notes C-4 an D-4 would let me hear and write this :
|C-401......|F-403......|G-403......|D-503......
|...........|...........|...........|...........
|...........|D#403v20...|...........|...........
|...........|...........|D-403v20...|C-503v20...
|D-401......|G-403......|A-403......|E-503......
|...........|...........|...........|...........
|...........|F-403v20...|...........|...........
|...........|...........|E-403v20...|D-503v20...
This feature was implemented in IT as machinesmith told me here (http://forum.openmpt.org/index.php?msg=28815.0&highlight=#28815), and also in Schism Tracker.
This would allow to simulate layered instruments or complex arpeggios both for playing and tracking.
Possible extension of this : hitting several keys would enter a "chord" of this template : by shift-selecting enough tracks (in chord mode), hitting x keys simultaneously would play/edit x templates (following the notes played).
Hmmm, This Legovitch guy is onto something, I best advise you to listen to him! IMPLEMENT! (Please... :cry: )