A special MIDI control message specifically designed to produce a change in pitch in response to the movement of a pitch bend wheel or lever. Pitch bend data can be recorded and edited, just like any other MIDI controller data, even though it isn’t part of the Controller message group. Behind the scenes, at a bits and bytes level, pitch bend messages are actually fairly complex and appear to break a lot of the conventional rules of MIDI data protocol. Pitch bend messages were designed to be able to hold and transmit a lot more data than most MIDI messages primarily because it can take a lot of data to produce a truly smooth (as in unquantized) bending of pitch over a potentially broad range. If pitch bend messages were handled like most other continuous controller messages you would often hear a noticeable stair-stepping quality to the bends. Without going into too much detail, pitch bend messages have a conventional status byte, which is followed by two data bytes. Some MIDI instruments makes use of only one of these, while others use both, so the data is formatted in a specific way so all instruments are able to communicate and discern the intended amount of pitch bend desired from one platform to another. Fortunately all of this madness goes on behind the scenes for the most part. Most software sequencers deal with it behind the scenes. An exception would be older sequencers that may show all of this data in an event list view. In those cases editing pitch bend data can get pretty challenging and requires a deeper understanding of the subtleties. Another element to consider is that a lot of complex pitch bend data can potentially cause some MIDI log jam problems, especially when there is a lot of other controller and/or MIDI clock or MTC data on the same cable.