MIDI is an acronynm for Musical Instrument Data Interface. This is a current loop serial interface with a a standard protocol for communication between keyboards, electronic musical instruments and computers. This protocol includes codes for describing music data, such as note on and note off messages (sent when a key is pressed and released) among other codes.
MIDI Channels
The MIDI protocol allows sixteen different channels of data to be transmitted on a single MIDI cable. Generally instrument voices only respond to one channel at a time. Multi-timbral instruments can respond to multiple channels with different sounding voices.
Rodgers Implementation
Rodgers organs always transmit note data on channels 12 and up. There is usually a group of switches (pistons below the great manual) that enable lower MIDI channels when engaged. More expensive organs have two switchable channels for each manual, like, MIDI GT A and MIDI GT B (great manual A and B channels). Only enable one of these when setting up the keyboard (maybe B for Bells).
Millennium/Platinum Implementation
The Millennium/Platinum carillon can respond to two MIDI channels simultaneously, and we refer to them as Primary and Secondary. When setting up a system with an organ, the Primary channel is typically the lower manual (Great) which is used for the melody bell voice and the Secondary channel is set to the upper manual (Swell) which is used for a harp voice.
When the Millennium carillon is placed in the System Setup - Keyboard Size/Midi menu it is looking for the highest and lowest MIDI note values and channel values for each keyboard. When it sees multiple channels (like it would with a Rodgers organ), it chooses the lower channel available. As of firmware 0311, we are only looking at the first two channels received.
MIDI Volume
On the Platinum/Millennium Carillon, note velocity affects not only the volume level of the note but also the brilliance of the note. Playing vigorously will be brighter and louder, playing gently will be duller and quieter.
Organs do not typically have a touch sensitive keyboard. Instead we have to rely on the expression pedal (in the case of an electronic organ). On an Allen organ, the expression shoe controls the note velocity values affecting both volume and brilliance.
On a Rodgers organ, the expression shoe sends MIDI Channel Volume data. If we only used this to change the volume of the chime output, we would lose the brilliance component of the bell dynamics. When volume data is detected, along with a steady state velocity, the Millennium MIDI input substitutes the volume value for velocity on the notes received. So a Rodgers expression shoe will provide the same dynamic changes that an Allen would.
Firmware versions prior to 0411 would accept volume levels of zero and mute the output. This is now ignored since we have run across a Solid State Logic midi interface (probably not installed and setup correctly by the organ technician) that sent a volume zero command every time the MIDI output was enabled.
MIDI File Import
Only single track MIDI Format 0 files are compatible with Management Suite. Without the Recording Librarian option, a supported carillon can only store one MIDI file at a time in the recording buffer.
It is important to transpose the music properly for the bell voice you will use to play it back. Automated chimes and carillons are always transposed to ring the largest bell on middle C, or C4 (Midi note 60) regardless of their true pitch. Millennium Cast Bronze carillon voices range from C3 to C8. Millennium Chime and harp selections use a split keyboard with the harp from C3 to Bb5 and the chime from B5 to C8. Notes above and below these ranges are prohibited.
Version 5.0 of the Management Suite and firmware version 0215 eliminate the restriction of temp and CPQ given below. The new software/firmware will successfully import and faithfully perform a MIDI file having tempo and time signature changes.
Version 4.7 of the Millennium Suite supports importing MIDI files to the carillon if it is equipped with the Recording Librarian option.
Versions 4.7 to 5.0 do not support any meta-data such as tempo or time signature changes embedded within the file after the first Note ON. In addition make sure the following parameters are set in the sequencer when saving the files:
| Tempo | 100 |
| Clocks per Quarter note | 120 |
| Bank | 0 |
| Patch | 0 |
Some users have noticed that stacking lots of notes in fast changing chords may overload the playback engine of the carillon or bell controller resulting in a slight slowing of playback tempo. Quickly arppegiating dense chords will avoid this slowdown without a noticeable change of arrangement. Such an arrangement is also more pleasing to the ear of the average listener.