Omni Mode

In MIDI keyboards this refers to a mode where an instrument will respond to MIDI coming in on any MIDI channel. The term is actually somewhat vague to properly represent a true mode of MIDI operation (see WFTD: MIDI Mode), but was used mostly in the early days of MIDI where the simple concept that an instrument would respond (or not) to data on any channel was important. Today when this term is used it is generally implied that MIDI Mode #1 is being discussed.