Technical Questions Answered by Vic Lennard
Q I am a professional guitarist/vocalist/songwriter who would like to use a sequencer for my live backing tracks. I currently have an Amiga 500 with an added half meg board and use Sequencer One and Super Jam. I don't really wish to take my computer to live gigs so I would like to know of a sequencer which would be compatible with the Amiga but also, hopefully, fairly user-friendly and without a long load time between songs.
A The two programs that you own go together nicely; Super Jam will create backings of guitar, piano, bass, strings, drums etc., which can then be saved as a MIDI File and loaded into Sequencer One where you can make any alterations.
If you intend to use a sequencer on stage, you are right to be concerned about taking a computer out with you, as most are not designed for the rigours of live work. If, as you say, you want to keep the delay between songs to a minimum, you need a device such as a MIDI File playback module which will play them back directly from disk rather than load them into memory - a process which can be very time consuming.
If you use the Export function in Sequencer One, you are given the option of saving a song as either a Format 0 or Format 1 MIDI File. The difference is that a Format 0 file has all MIDI information merged into a single track while a Format 1 file leaves all individual track information intact. Some of the cheaper MIDI File playback devices - such as Yamaha's MDF-2 which retails at £299 - can only read Format 0 files, so if this is your choice, make sure that you use the Format 0 option on Sequencer One. Format 1 MIDI Files (such as those supplied by commercial song libraries) will need to be loaded into Sequencer One and converted to Format 0 before they can be used.
A more expensive unit like Roland's Sound Brush SB-55 (which retails at £549) can read both Format 0 and Format 1 MIDI Files and includes a remote controller - which could be very handy on stage.
It's also worth noting that if you start working with Sequencer One and find that you like it, the upgrade - Sequencer One Plus - offers extra facilities such as a Tempo Map, where you can graphically draw in tempo changes, and a Jukebox facility which lets you chain various songs together for immediate playback - something you may wish to consider if you change your mind about using a computer live. More information from Gajits on (Contact Details).
Returning to non-computer solutions: if the options mentioned previously are too expensive, you could buy a disk player which doesn't read MIDI Files, but relies on the transfer of songs via its MIDI In port (connected, in your case, to the MIDI Out from the Amiga MIDI interface). With such a system, you could effectively 'play' your songs into the disk player which would record them much like a tape machine. The Elka CR-99 MIDI Data Player - though now discontinued - would be a machine to look out for here. You might be able to find one secondhand for around £150.
Incidentally, after mentioning commercially available MIDI Files earlier, it's perhaps worth pointing out most of these are released as IBM PC or Atari ST formatted disks which the Amiga cannot read. However, a utility called MultiDOS' is available from Zone Distribution ((Contact Details)) for £5 which will read such disks and allow you to load MIDI song files into Sequencer One where you can change the MIDI channels and MIDI Program Change numbers to suit your equipment.
A First let me give you the basics on General MIDI. As many aspects of the MIDI specification are optional, manufacturers in the USA and Japan have defined a specific set of MIDI functions which any piece of equipment sporting the GM System logo (Figure 2) has to conform to. These include:
- The ability to play up to 16 instruments (timbres) on any MIDI channels - all GM modules are 16-part multitimbral.
- Key-based drums assigned to MIDI channel 10 and following the 47-instrument set-up defined in the General MIDI Percussion Map.
- A minimum of 24 simultaneously available voices, possibly with 8 reserved for percussion and 16 for other instruments.
- 128 presets each assigned to the MIDI Program Change number in the General MIDI Sound Set.
- Recognition of certain MIDI Control Changes including; Modulation (#1), Volume (#7), Pan (#10), Expression (#11) and Sustain Pedal (#64).
- Recognition of Channel Aftertouch and Pitch Bend.
Conformity to this protocol should ensure a significant degree of compatibility between General MIDI sound modules - no notes cutting out due to different polyphonies, no incorrectly selected sounds via MIDI Program Changes, no incoherent drum patterns due to the wrong mapping - and so on.
Roland's GS is a superset of General MIDI. By using MIDI Bank Select messages, more than 128 sounds are available - the Sound Canvas SC-55, for instance, has 317 in total - and a hierarchical structure is used so that the absence of these extra sounds on some modules will always point back to the original GM sound - or Capital Tone as Roland call it. There are also some additional MIDI Control Changes such as Chorus depth and Reverb depth.
As for what 'GS' stands for, that's easy - nothing at all! Roland were originally going to call the system 'GSS' - for General Synth Standard - but decided to remove the word 'Standard' and call it, simply, 'GS'.
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