Sequencer.SyncMode (Java Platform SE 8 )
Keywords: javax.sound.midi.Sequencer.SyncMode class
Date: 2026-04-24

javax.sound.midi

## Class Sequencer.SyncMode

- java.lang.Object
- - javax.sound.midi.Sequencer.SyncMode

- Enclosing interface:
    Sequencer

      public static class Sequencer.SyncMode
      extends Object

  A `SyncMode` object represents one of the ways in which a MIDI sequencer's notion of time can be synchronized with a master or slave device. If the sequencer is being synchronized to a master, the sequencer revises its current time in response to messages from the master. If the sequencer has a slave, the sequencer similarly sends messages to control the slave's timing.

  There are three predefined modes that specify possible masters for a sequencer: `INTERNAL_CLOCK`, `MIDI_SYNC`, and `MIDI_TIME_CODE`. The latter two work if the sequencer receives MIDI messages from another device. In these two modes, the sequencer's time gets reset based on system real-time timing clock messages or MIDI time code (MTC) messages, respectively. These two modes can also be used as slave modes, in which case the sequencer sends the corresponding types of MIDI messages to its receiver (whether or not the sequencer is also receiving them from a master). A fourth mode, `NO_SYNC`, is used to indicate that the sequencer should not control its receiver's timing.

  See Also:
    `Sequencer.setMasterSyncMode(Sequencer.SyncMode)`, `Sequencer.setSlaveSyncMode(Sequencer.SyncMode)`

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static Sequencer.SyncMode` | `INTERNAL_CLOCK` A master synchronization mode that makes the sequencer get its timing information from its internal clock.
    `static Sequencer.SyncMode` | `MIDI_SYNC` A master or slave synchronization mode that specifies the use of MIDI clock messages.
    `static Sequencer.SyncMode` | `MIDI_TIME_CODE` A master or slave synchronization mode that specifies the use of MIDI Time Code.
    `static Sequencer.SyncMode` | `NO_SYNC` A slave synchronization mode indicating that no timing information should be sent to the receiver.

  - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `protected` | `SyncMode(String name)` Constructs a synchronization mode.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `boolean` | `equals(Object obj)` Determines whether two objects are equal.
    `int` | `hashCode()` Finalizes the hashcode method.
    `String` | `toString()` Provides this synchronization mode's name as the string representation of the mode.

    - ### Methods inherited from class java.lang.Object

      `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- - ### Field Detail

    - #### INTERNAL_CLOCK

          public static final Sequencer.SyncMode INTERNAL_CLOCK

      A master synchronization mode that makes the sequencer get its timing information from its internal clock. This is not a legal slave sync mode.

    - #### MIDI_SYNC

          public static final Sequencer.SyncMode MIDI_SYNC

      A master or slave synchronization mode that specifies the use of MIDI clock messages. If this mode is used as the master sync mode, the sequencer gets its timing information from system real-time MIDI clock messages. This mode only applies as the master sync mode for sequencers that are also MIDI receivers. If this is the slave sync mode, the sequencer sends system real-time MIDI clock messages to its receiver. MIDI clock messages are sent at a rate of 24 per quarter note.

    - #### MIDI_TIME_CODE

          public static final Sequencer.SyncMode MIDI_TIME_CODE

      A master or slave synchronization mode that specifies the use of MIDI Time Code. If this mode is used as the master sync mode, the sequencer gets its timing information from MIDI Time Code messages. This mode only applies as the master sync mode to sequencers that are also MIDI receivers. If this mode is used as the slave sync mode, the sequencer sends MIDI Time Code messages to its receiver. (See the MIDI 1.0 Detailed Specification for a description of MIDI Time Code.)

    - #### NO_SYNC

          public static final Sequencer.SyncMode NO_SYNC

      A slave synchronization mode indicating that no timing information should be sent to the receiver. This is not a legal master sync mode.

  - ### Constructor Detail

    - #### SyncMode

          protected SyncMode(String name)

      Constructs a synchronization mode.
      Parameters:
        `name` - name of the synchronization mode

  - ### Method Detail

    - #### equals

          public final boolean equals(Object obj)

      Determines whether two objects are equal. Returns `true` if the objects are identical
      Overrides:
        `equals` in class `Object`
      Parameters:
        `obj` - the reference object with which to compare
      Returns:
        `true` if this object is the same as the `obj` argument, `false` otherwise
      See Also:
        `Object.hashCode()`, `HashMap`

    - #### hashCode

          public final int hashCode()

      Finalizes the hashcode method.
      Overrides:
        `hashCode` in class `Object`
      Returns:
        a hash code value for this object.
      See Also:
        `Object.equals(java.lang.Object)`, `System.identityHashCode(java.lang.Object)`

    - #### toString

          public final String toString()

      Provides this synchronization mode's name as the string representation of the mode.
      Overrides:
        `toString` in class `Object`
      Returns:
        the name of this synchronization mode

Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2026, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.