Note: This topic relates to SONG mode, or BSEQ's which have been imported into SONG mode via a SMF. I wanted to be able to convert some of my i-Series SONGS's into GM format. The main problem was that some of my SNG's used the i-Series Percussion Kit (Kit 6), sometimes because I had used a percussion track imported into SONG mode from a STYLE. The answer was to transpose the notes on the percussion track, so that they mapped to the same (or similar) drum sounds on the General MIDI drum kit. This could also prove useful if you want to get some STYLE PERC tracks, into your sequencer in GM Kit format.
One method is to use the SHIFT NOTE option, to manually transpose all the drum notes individually. This is limited because the maximum shift allowed is 24 semitones. This means that if you need to transpose your notes more than 24 ST, you will have to keep repeating the process until the desired target note is reached, being careful to select intervals of transposition that will not clash with existing notes on that track.
Fortunately there is a much better way using several programs written by Guenter Nagler, and are freely available from his web site.
The programs you need are Midipat, Miditran & Midi2GM. By creating a dedicated conversion table (in this case to convert i-Series Percussion Kit to GM drum kit) Midipat can be used to automatically carry out all the transpositions required. To do this I created a dedicated conversion table (iPerc2GM.pat) which contains all the transpositions of the i-Series Percussion Kit to the GM kit equivalents. The patch files *.PAT are text files that can be easily edited with any text editor. Please note that not all of the i-Series percussion sounds are available in the GM kit. Where there was not an exact match I have tried to map the original sound, to a similar sound in the GM kit e.g. SynCowbell maps to Cowbell, and Baya's map to Toms (which is a bit drastic!).
In GM the drum kit is always on MIDI channel 10. This means that we eventually need our modified percussion track to be mapped onto channel 10. Before I do this I want to adjust the VELOCITIES of the notes on the percussion track, so that they sound at the correct volume when merged with the drums on channel 10, which will tend to have a higher TRACK VOLUME. The program Miditran enables one to lower the velocities of all the notes in a specific track of a SMF.
Finally, Midi2GM can be used to map the midi channel of our percussion track to channel 10. i.e. this in effect merges the original drums on channel 10 with our modified percussion track, so that we now get drums & percussion playing on MIDI channel 10, using the standard GM kit.
Example:
Let's assume we have a SONG already loaded, and that we have a DRUM TRACK on channel 10 (GM kit) and a PERCUSSION TRACK on channel 11 (Kit 6). Note: It's the MIDI channel that is important 'not' the TRACK number, although by default the TRACK numbers normally correspond to the same MIDI channel i.e. TRACK 10 is normally assigned to MIDI channel 10 etc. Let's also say that the DRUM track has volume 127 and the percussion track has volume 100. I would then carry out the following steps:
i) Change the PROGRAM on your PERCUSSION track to the GM kit, and set the track volume to the same volume as the DRUM track i.e. 127. This is to ensure that when the tracks get merged the program and track volume on channel 10 does not get changed, by other control changes that are also on channel 11.
ii) Save the song as a SMF e.g. source.mid. I think it's best to save using FORMAT 0, as most GM players do not play FORMAT 1 midi files correctly.
iii) Using your PC, Copy the files Midipat.exe, Miditran.exe, Midi2GM.exe and iPerc2GM.pat to your PATH.
iv) Now create a batch file e.g. iPerc2GM.bat as shown below.</P>
v) Finally all we need to do is run the batch file with the following command: iPerc2GM source.mid -27, where -27 is the difference between the DRUM & PERC track volumes in this example, and source.mid is the source MIDI file. The converted MIDI file is saved as output.mid. Once you have set up the batch file, you can now quickly convert percussion tracks to GM. Hint: If you load the SMF back into your synth, you have gained a free track, because the DRUMS & PERC are now combined onto 1 track!
i) Latin.mid is a converted DRUM & PERC section from a Latin i-Series ROM style.
ii) MamboPrc.sng contains a Mambo PERC track using kit 6 in SONG0, and the mapped version using the GM kit in SONG1. They should sound the same, except for panning.
