Band-in-a-Box (BIAB) is a MIDI music arranger software package for Windows and macOS produced by PG Music Incorporated. The software allows the user to create songs by simple keyboard inputs: a musical style , a tempo and a key. The user types chords, even complex ones, and the software generates a song. BIAB can create backgrounds for almost any chord progressions used in Western popular music, and can play them in any of thousands of different music styles. It was first introduced in 1990 for PC computers and the Atari ST. “PG Music” gets it name from Canadian Peter Gannon, the creator of Band-in a Box.[1]Early versions of the software featured only midi (musical instrument digital interface) data, but later editions included recordings of real musicians playing all the specified instruments in a convincing fashion, often emulating the phrases of top musicians.[1]In BIAB, styles refer to musical styles encapsulated in style files (*.STY). Thousands of styles are included in most BIAB installations. Styles can be MIDI only, a combination of MIDI and RealTracks/RealDrums, or RealTrack/RealDrums only (called RealStyles).

Users can create their own styles by:

• Editing existing styles
• Importing styles from MIDI files
• Using BIAB’s StyleMaker

Band-in-a-Box MultiStyles can have up to 24 substyles. Original Band-in-a-Box styles have two substyles, referred to as A. and B. Typically, A may be used for the main parts of a song, and B for its bridge. B. substyles may contain more instruments, or be fuller-sounding in some other way (e.g. four-beat rhythm rather than two-beat).

BIAB also works with MIDI programs like Finale, Garritan Personal Orchestra, and similar packages.

When users play songs in BIAB, they can vary its key, tempo and style, and change the number of times any section of the song repeats. With the Melodist and Soloist features, the user can select instruments and other details; BIAB then creates tracks based on these selections. The Melodist and Soloist tracks can be edited note-by-note in the Notation window. Leadsheets of each track can be printed for a live band, or for practice.

Songs can be exported as MIDI or audio files. After exporting to a MIDI file, users can edit the BIAB-generated background in a MIDI sequencer like RealBand or PowerTracks. Songs created in BIAB can be burned to CD or copied to media-playing devices.

BIAB used only MIDI until 1999, when digital audio was added, letting users record vocals and instruments directly into their songs. The Audio Chord Wizard, released with the 2007 version of BIAB, lets users to choose any audio song from their computer; the Audio Chord Wizard then analyzes it and produces the chord progression for it.

In November 2006, PG Music released “RealDrums”, providing users with tracks recorded by real drummers. One year later, “RealTracks” was introduced, providing the same for pianos, bass and guitars, as well as soloing instruments such as saxophones, guitars, and pedal steel. These features have been expanded over the years; as of 2012, over 200 RealDrums and 800 RealTracks were available. RealTracks uses the élastique Pro V2 time-stretching and pitch-transposition engine by zplane.development, which allows the prerecorded live instruments to retain much of their natural sound when the tempo and pitch is varied.

Several versions of BIAB are available. Larger versions are sold preinstalled on hard drives, due to the size of the audio files. Uncompressed RealTracks and RealDrums WAV/AIFF files are also available for lossless audio use.