Answer: Acoustic instruments
In reply to Jeff Parton's query in AMPLINEX 005, one of the
better series on this topic I've read in the last six months appeared in Music Technology
magazine (August to October 1987). The series covered synthesising acoustic
guitar, clarinet and the snare drum. Admittedly, the actual patches supplied
were for FM, phase distortion and analogue synthesisers, but the material makes
interesting reading.
As for other sources of information, your local university
library may be able to help. I know the one I use (the Andersonian at
Strathclyde University) has some books on the physics of music which include harmonic
spectra.
However, using the current waveforms supplied with the
Hybrid Music System, your chances of simulating the instruments realistically
are slim, but with some perseverance you should get some reasonable results.
Your other alternative, I suppose, is SoundSculptures'
Waveform Designer. Have any AMPLINEX members bought this product? A user report
please!
Scott Mackie
Answer: Acoustic instruments
I know of two books containing the harmonic spectra of
instruments. These are:
Music Physics and Engineering by Harry F Olson
and
Psychology of Music by Carl E Seashore
Both are published by Dover Books and the original editions
were quite old - 1952 and 1938 respectively.
I sent to America for my copies but they are available in
the UK from two sources:
IMP, Woodford Trading Estate, Southend Road, Woodford Green,
Essex. IG8 8HN
Telephone 01 551 6131
Telephone 01 551 6131
The 1987 catalogue lists the prices as Olson £7.95 and
Seashore £6.95.
Music Sales Ltd., Newmarket Road, Bury St. Edmunds, Suffolk.
IP33 3YB
Telephone 0284 702600
Their catalogue lists the prices as Olson £5.50 and Seashore
£4.95 but you should check these too.
The spectrum plots are just a part of the books and someone
may well know of another source. One worth checking out - I haven't seen it yet
- is
A Synthesist's Guide to Acoustic Instruments by Howard
Massey
£14.95 from Music Sales.
Ian Waugh
Question: Grace notes in Staff
Is there any way of putting grace notes into music, via the
Staff editor (I nearly always work in this module)?
If not, do I have to add them afterwards in Notepad, and if
so, how?
Diccon Maude
Question: Music 2000 Power Supply
I intend to purchase the Music 2000 MIDI interface and I
understand that this unit takes it power from the computer. As I have a fully
loaded BBC Model B (disc drive/ROM board etc.) I would like to know what
voltages and what current this unit requires so that I can buy or build a
suitable power supply.
Les Pearce
The Music 2000 MIDI interface consumes 5V at 100mA. This is
such a small amount, it would be better to make a power supply for your disc
drives if you think your computer's power supply is close to its limits.
Answer: The 'Syncer' waveform
Regarding Jeff Parton's question about the 'Syncer' waveform
(AMPLINEX 005):
The 'Syncer' waveform doesn't have a harmonic spectrum
because all of its harmonics have a zero volume. Its main use is in modulating
other waveforms using synchronization (SYNC - see the Music 5000 User Guide
pages 69-70).
The 'Syncer' waveform is placed on the EVEN channel and
resets the phase of the ODD channel's waveform each time its own phase passes
through zero or the EVEN channel's auxiliary output signal, (sign version of
the waveshape, +/-), is negative.
With 'Syncer' on the synchronizing (EVEN) channel the ODD
waveform is reset only when the EVEN channel's phase passes zero (effectively
after one waveform cycle). By varying the frequency of the modulated channel
the point where 'Syncer' restarts the modulated waveform varies dynamically, giving
tone changes.
Using waveforms other than 'Syncer' on the modulating (EVEN)
channel gives more complex and unpredictable results.
Mark A J Mulders
Question: Broken chords in Staff
Broken chords can be written and will play okay in Notepad
yet the '! Bad bar' error appears when playing from the Staff. I am a little
confused. Doesn't music entered in the Notepad automatically become written in
the Staff also?
Andy Knight
Answer: AMPLE DCT 'split' utility
In reply to Robin Johnson's problem with the Music 4000
'split' utility (AMPLINEX 005), I too could not get it to work - until I read
the AMPLINEX feature on the ACT command! This made it obvious that the closing
)ACT was missing.
The error lies in the word "split". After
IF(ACT)IF
and before
0 spitch #!
you should insert )ACT. It then works as described.
Bernie Dawson
Answer: Tuning systems in AMPLE
Further to Bob Cornford-Wood's question in AMPLINEX 005:
Alternative tunings are fascinating and I'd be very
interested in any work done in this area on the Music 5000 although I suspect a
resolution of 192 is not enough for some applications. Quite a few of the new
synthesisers have alternate tuning facilities, e.g. the TX81Z - I'm just
waiting for someone to write some music for them.
Another area of potential exploration is Micro Tuning - the
division of the octave into more (or less) than 12 tones. An American called
Easley Blackwood did this the hard way - with a traditional keyboard and old synthesisers
- and produced a record of pieces he'd composed by dividing the octave into 13
to 24 intervals. All this in 1980!
The record was produced by himself as far as I can tell
although it bears the number E639. The only available source I know is Easley
Blackwood himself and the last address I have on him (from 1982) is
The University of Chicago, The Department of Music, 5845
South Ellis Avenue, Chicago, Illinois 60637, USA.
The price then was $12.
Ian Waugh
The Utilities section of this issue of AMPLINEX contains a
program which allows Just Temperament to be used.
Question: Staff editor corruption
After using AMPLINEX, if I want to go back to MAIN, I select
'Exit from AMPLINEX', and when the menu appears, select 'New Program'. If I
then want to enter the Staff editor, I select this.
When Staff editor is loaded, almost every symbol is
corrupted - the bar line comes out as a 'squiggly line', the treble clef is a
mixture of the accidentals and the different note lengths, and the time
signatures contain the symbols for triplets(3), duplets(2), and accidentals.
What has happened? I have to press Ctrl-Break or turn the
computer off, and load the System disk again. Has anyone else had these
problems? It may, of course be the other ROMs in the computer.
Diccon Maude
I have been unable to reproduce the effect you describe. The
AMPLINEX control program (A.MPLINEX) is written entirely in AMPLE and should
cause no problems. The 'Exit from AMPLINEX' option performs a 'NEW' command and
should leave the system as it found it.
I would therefore suspect some other cause - perhaps those
ROMs you mention.
Question: Pitch glide via ACT
Since reading about the ACT command I have been wondering if
it is possible to use this to get pitch glides from note to note whilst playing
the Music 4000 keyboard (as opposed to programming in such effects using Slide).
Presumably this would mean keeping track of the previous
note, comparing it with the new one, working out the difference and using ACT
to glide to the new note, all the time checking to see if another new note has
been struck! That's all very well in theory, as they say, but I don't know how
to program it even if it is possible.
Bernie Dawson
Question: Booting the Music 4000
My Music 4000 disc is marked 40/80 track yet I can only get
it to boot with my disc drive switched to 40-track. This is annoying because my
AMPLINEX disc is 80-track and only having a single disc drive I am constantly
readjusting the 40/80 track switch. I there something I can do or do I have to
fork out for dual drive?
Andy Knight
Question: The RUN command
I have written some pieces on the Music 4000/5000 system,
and saved them, but I cannot get them to run with the RUN command. Perhaps, as
it is the name of the piece it should have a certain format? Any answers?
Peter Gray
Every music program should have a word called 'RUN' which
contains at least the
"1..." PLAY
command to start the music. This is the word which is used
by the 'RUN' option on the Main menu. Looking at your music contributions, you
seem to be using the title of the piece instead of the word 'RUN' and this is why
you can't use menu option. Look at pages 77-78 of the Music 5000 User Guide for
more details.
Editor's note:
Due to the large response to the question in AMPLINEX 005 by
Bob Cornford-Wood about the Opus Challenger disc system, there is a separate
article in the Features section of this issue.
The comments following some of the questions above are only
my opinions on the subject and should not be taken as definitive answers.
Your comments are most welcome on any of the questions
posed, whether they supplement, confirm or correct any I have expressed.
Published in AMPLINEX 006, July 1988
