Akai MPC Reference Manual page 117

MIDI Thru has a special function. It allows the sender to transmit to several receivers. It routes the
incoming signal to the next device without modifying it. Another device is simply connected to this
jack, thus creating a chain through which the sender can address a number of receivers. Of
course it is desirable for the sender to be able to address each device individually. To achieve
this, a MIDI channel message is sent with each MIDI event.
MIDI Channel
This is a very important element of most messages. A receiver can only respond to incoming
messages if its receive channel is set to the same channel as the one the sender is using to
transmit data. Subsequently, the sender can address specific receivers individually. MIDI
Channels 1 through 16 are available for this purpose.
MIDI Clock
The MIDI Clock message transmits real-time tempo information to synchronize processes among
several connected devices, e.g., a sound generator's delay time to a MIDI sequencer.
Modulation
A modulation influences or changes a sound-shaping component via a modulation source.
Modulation sources include envelopes, LFOs or MIDI messages. The modulation destination is a
sound-shaping component such as a filter or a VCA.
Note On / Note Off
This is the most important MIDI message. It determines the pitch and velocity of a generated note.
A Note On message will start a note. Its pitch is derived from the note number, which can range
from 0 to 127. The velocity lies between 1 and 127. A velocity value of 0 is equivalent to a "Note
Off" message.
Normalize
Normalize is a function to raise the level of a sample to its maximum (0 dB) without causing
distortion. This function automatically searches a sample for its maximum level and consequently
raises the entire sample's level until the previously determined maximum level reaches 0 dB. In
general this results in a higher overall volume of the sample.
Panning
The process or the result of changing a signal's position within the stereo panorama.
Pitchbend
Pitchbend is a MIDI message. Although pitchbend messages are similar in function to control
change messages, they are a distinct type of message. The resolution of a pitchbend message is
substantially higher than that of a conventional Controller message. The human ear is
exceptionally sensitive to deviations in pitch, so the higher resolution is used because it relays
pitchbend information more accurately.
Program
A Program is a file that contains a list of all samples to be used, and settings for each sample (i.e.,
pad assignments, loop points, pitch tuning, effects, etc.) The MPC's PROGRAM EDIT mode is
where you can edit and assign samples. The MPC software can have a total of 128 programs in a
Project.
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