Besides making bell sounds using digitised samples that are sent to your PC loudspeakers using DirectX, Abel can also use MIDI. This is a technology that allows note and effect information to be exchanged between synthesisers, computers, music keyboards, and other electronic musical devices.

As far as your PC and Abel are concerned, there are two types of MIDI device:

• Built in as part of your sound card driver. This type of MIDI device will receive the MIDI messages that Abel sends out, but will generate the sounds within your sound card and send them directly to your PC loudspeakers. The driver for this type of device often has the word "synth" in its name (e.g. "AWE64 MIDI Synth"). These devices usually support the General MIDI specification (see below)
• An external device such as an electronic musical keyboard or synthesiser, attached to your computer via a MIDI cable. This will have a driver in your computer that often describes itself as "out" (e.g. "AWE64 MIDI Out"). If you select this type of driver, and you do not have an external device connected to your computer (or it is switched off), you will not hear any bell sounds.

External MIDI synthesisers often support "sampling" whereby you can play a sound into the synthesiser and it will then play that sound back at different pitches. If you have one of these keyboards, this can be an easy way of getting Abel to use the sounds of your own bells.

You can see a list of the current MIDI device drivers installed in your computer by going to the Sound Options Dialog in Abel and clicking on the MIDI Output Device drop-down box.

Abel's MIDI support is limited, and there are several things to note:

• You must restart Abel after changing from DirectX to MIDI or vice-versa
• The MIDI Patch number tells your MIDI device which musical instrument to use. General MIDI (see below) standardises the names of these instruments, but external synthesisers may use arbitrary patch numbers. MIDI devices use patch numbers from 0 to 127; however, some devices or programs use numbers starting at 1, and may talk about "program change" instead. This clearly can be confusing, and you may need to do some experimenting or read the documentation that came with your synthesiser to help you choose an appropriate number for Abel to use. As a guide, if you want to use General MIDI instruments, subtract 1 from the General MIDI program change number (see General MIDI below)
• Abel never sends MIDI "Note Off" messages. This means any notes sounded by Abel will sound continuously until the program exits or a different sound configuration is chosen. Therefore, you should choose instruments or sounds that have a naturally decaying sound (e.g. tubular bell) rather than continuously sounding instruments (like organ)
• MIDI supports 16 channels, which allows you to send messages to 16 different instruments simultaneously. However, your MIDI device may reserve one or more channels for a particular purpose (e.g. a device that supports General MIDI will reserve channel 10 for drums. The effect of choosing the drum channel can be quite amusing.). Normally, unless you know what you are doing and you know that you need to use a particular MIDI channel, you will not need to change Abel's default channel number.
• Consult the documentation for your MIDI device if in doubt.
• If you change the number of MIDI device drivers in your system - e.g. by installing a new sound card or by adding external drivers to an existing sound card - and Abel was configured to use a MIDI device, you will need to use the Sound Options dialog to check which MIDI device Abel is using, as it may not be the one you expect after the change.

The MIDI specification does not describe what instruments correspond to which patch numbers. This was deliberate, as MIDI was intended for professional musicians to assemble a custom palette of musical sounds. General MIDI was devised once MIDI started to be adopted by the general public, and defines a standardised patch map (so that, for example, a Grand Piano sound is always the same number) in order that users could exchange MIDI files with some hope that they might sound somewhat similar on someone else's computer.

General MIDI only defines the program change numbers and the instrument names; it does not define what those instruments actually sound like, and as a result the quality of reproduction varies enormously from one device to another.

Abel is configured by default to send patch number 14 to your MIDI device, which corresponds to program change number 15 "Tubular Bell" in the General MIDI specification.

You can find a description of General MIDI and the instruments and corresponding program change numbers here: MIDI sound set.

See also:

  Sound options