Roger Sapolsky
The points discussed here will be of interest to those who,
like me, have tried using the MIDIBEND instruction on a Roland D110 (or D10, or
MT32) and have found the information given in the Music 2000 User Guide (see
pages 42 to 46) is too brief, and is in some cases misleading.
Consider for instance 'sb' at the top of page 43. The score
following it will not play a D unless the 'Bender Range' (let's call it 'BR')
of the instrument is set at 8 (the default being 12). This setting can be done manually
on the D110 front panel, but it is obviously better to let the program do that
for you. The exclusive message to enter after SCORE has the form:
-1 &41 &10 &16 &12 address value checksum sysex
The bytes &F0 and &F7 which start and terminate all
exclusive messages are provided by 'sysex', see page 56.
The other variables are explained below:
address - the address map in the Roland D110 user manual
lists the addresses of the 'timbre temporary area' used by each of the 9 parts,
or players. For player 1, this is hex 03 00 00, for player 2 it is 03 00 10, etc.
Chart 5-2 indicates that 00 04 must be added to the address to reach the BR, so
the address to use for player one's BR is 03 00 04.
checksum - to calculate this, convert the 3 bytes of
'address' and the byte 'value' (if given in hex) into decimal, and sum up the 4
numbers. If the total is <= 128, subtract it from 128. If it is larger than
128, subtract it from 256. The result converted into hex is the checksum.
This gives the full message:
-1 &41 &10 &16 &12 03 00 04 8 &71 sysex
value - this is the required BR. A BR of 8 (giving the
multiplier 1024 found in words such as 'sb' and 'gl') produces a bend of one
semitone.
Larger BRs can be used, provided the multiplier 1024 is
reduced to lower values in all word definitions, as shown by this chart:
semi-tones
(*) max bend
BR checksum multiplier up down
-------------------------------------
8 &71 1024 7 -8
16 &69 512 14 -16
24 &61 341 24 -24
(*) max bend
BR checksum multiplier up down
-------------------------------------
8 &71 1024 7 -8
16 &69 512 14 -16
24 &61 341 24 -24
(* valid for player 1 only)
To experiment with the words given in the User Guide, it is
best to enter a normal mix9 including one instrument or more with parts 1a, 1b,
etc., each containing a particular trial. After saving the resultant program,
the words it contains are ready for SPOOLing and EXECing into other programs
where required.
Using 'slurbend' (Music 2000 User Guide, page 44) you may
have wondered why the third note in the score (C) sounds out of tune. This is
because C is located 10 semitones above the D preceding it, while the maximum possible
pitch bend is 7 semi-tones (using BR=8). The score should thus have been
written:
C ~D ~c c ~D
(the User Guide may have been corrected since I received
mine).
Another error occurs in the comments after the word 'glh'
(page 44): read "on 7th beat" instead of "on 3rd beat". At
least this one won't do any harm to your ears.
In the comments for the word 'gl' (page 44) it is not said
that a negative sign should be placed before the number of steps to play a down
slide - an explanation of this would have saved me a lot of time.
Finally, there are several examples given in the Music 2000
User Guide where beginners may wonder why they don't hear anything when
pressing f1.
Just as you enter
READY 1 VOICES Upright
in non-MIDI AMPLE, you should enter
1 VOICES MIDIV number MIDIPROGRAM
here.
If the Roland D110 user manual is to be believed, the BR can
be set using RPC (registered parameter control) numbers. Numbers 100 (LSB) and
101 (MSB) are given in the Roland MIDI implementation chart. I have tried a lot
of instruction configurations, but trial and error hasn't brought me the correct
answer, hence my use of the more complicated exclusive messages.
Included on this disc is a demonstration program, called 'F.Bendemo',
in which two saxophones play the introduction of an Ellington piece - four bars
with pitch bends. By the way, you should give up any hope of playing the slide
in the first bar of 'Rhapsody in blue' using MIDIBEND: it climbs up a record of
28 semitones!
Related file on this disc:
Published in AMPLINEX 020, November
1990
