Most guitar synths contain many high quality sounds, but by connecting an external MIDI sound source to their MIDI output (assuming it has one), it’s possible to massively expand the range of sounds available to the player, andany number of tones can be layered to create never-before-heard textures. MIDI outputs can also serve as a convenient and highly expressive input tool for entering data into a MIDIsequencer. The MIDI information is designed to transmit in what is termed the “Mono Mode” which means that the performance information for each string is output on its own separate MIDI channel. This affords a greater degree of expressive control as each string/channel carries its own note and Pitch Bend information. Working in this way makes it possible to reproduce unique guitar techniques such as whammy bar usage and harmonised string bending. The only proviso is that the external MIDI sound source is mulitimbral, offering six or more parts – very common these days.
It’s also often possible to transmit in “Poly Mode” whereby a single common channel is used for all strings. This is handy if your external sound module is not multitimbral, as is the case with some of the more recent modeling synths. However, it should be noted that when two or more strings are playing, Pitch Bend messages are not sent – instead, any bent notes will move in semitone steps. This of course is not a problem when trying to reproduce Piano or other normally chromatic parts. In Poly mode, accurate pitch bend IS still sent for single melodic lines. This can sometimes produce an interesting effect when your guitar is slightly out of tune – any solo lines are out of tune whilst any chords played fall perfectly in tune! In either mode, there is one very important setting to make within the guitar synth and in the external module if total chaos is to be avoided. The Pitch Bend Range must be set to the same value on the guitar synth and on all used channels on the external sound module. If this is not done, then any information conveyed as pitch bend will be distorted, giving rise to apparent mistracking and “bum” notes. Select the largest pitch bend range possible for both units to avoid annoying re-triggering during long slides.
When using the guitar synth as an input device to a MIDIsequencer, you will need to decide whether to work in the Mono or Poly mode. In this case it might be better to use the Poly mode if your sequencer can only record up 16 MIDI channels of performance data. If you have the luxury of a Multi-busMIDI setup and a few multitimbral sound modules or soft synths, then go ahead and use the Mono mode. Bear in mind however that in Mono mode, the amount of MIDI data being transmitted in a given time could be very large indeed. To reduce the data density without the need for tedious post record editing, some guitar synth base units offer a “Bend Data Thin” option which, when switched on, reduces bend data transmission substantially at the slight expense of the smoothness of pitch changes.
