Clock

Overview

This section describes the MIDI and AU host-based clock systems that synchronize the Event system.

Mass can be synchronized to musical time in a few ways:

  • With an internal MIDI sync clock
  • With an external MIDI sync clock
  • With host beat position information, if running the AUv3 version of Mass

A note about the transport

Mass is not a strictly linear sequencer and it does not have the concept of a "pause" state. Each time the transport is stopped it resets the play position. This is also the case if the transport is externally controlled via MIDI. The exception to this rule is when running Mass as an AUv3: Mass will start at the host's beat position, if it provides one.

Parameters

settings-clock.png

Note: this setting block does not show in the AUv3 version of Mass. When running as a plugin, Mass defers all clock-related duties to the host application. Mass will automatically synchronize with the host's beat position, if it provides it, and all MIDI sync clock behavior will be disabled.

Parameter: Tempo

Set the Composition tempo in BPM. This control is disabled if Parameter Clock Source is set to external.

Parameter: Clock Source

Allows changing MIDI sync clock source between internal and external.

Internal and External MIDI sync

Mass can operate an internal MIDI sync clock, or it can listen for external sync messages. The internal sync clock sends a MIDI Timing Clock message at a rate of 24ppqn, based on the tempo set by Parameter Tempo. If the parameter is set to external, the internal clock will halt and Mass will rely on an external device to send MIDI Timing Clock messages.

Note: when the parameter is set to internal, Mass will also send the MIDI Timing Clock message to its MIDI output. This allows you to configure Mass as the primary clock in a MIDI-connected setup.

Parameter: Transport Source

Allows changing the transport source between internal and external. If set to internal, the play/stop button on the [controls dock](Navigating Mass > Accessing control panels) will start and stop the transport, as well as send MIDI Start and MIDI Stop messages, respectively. When set to external, this control will be disabled and Mass will only start or stop when it receives MIDI Start or MIDI Stop messages from an external source.