Computer-based systems, devices, and methods for generating musical compositions that are purposefully synchronized with video are described. A video timeline is defined with various time-markers that demarcate specific events in the video. A music timeline is generated based on the video timeline. The music timeline preserves the various time-markers from the video timeline. A computer-based musical composition system generates a musical composition based on the music timeline. The musical composition includes various musical events that align, synchronize, or coincide with the time-markers such that when the video and musical composition are played together the musical events align, synchronize, or coincide with the demarcated events in the video.

Computer-based systems, devices, and methods for automatically generating aesthetic chord progressions and key modulations in musical compositions are described. Known harmonic relationships are expanded upon to produce a much richer set of harmonic transition probability models compared to conventional music theory, and these models are leveraged by a computer-based musical composition system to generate new musical compositions and variations of existing musical compositions. Techniques for enabling a computer-based musical composition system to automatically determine when to introduce a key modulation, what key to module to, and what chord progression(s) to use within the new key are all described.

A computer-implemented method for music composition embodying a system for teaching the same is provided. Each composition is retrievably stored as music data selectively broken apart into different elemental portions for generating and teaching the composition of hundreds of thousands of additional songs or accompaniments for over 40 musical instruments and all types of human voices. The present invention is adapted to allow the melodies of the additional songs or accompaniments to automatically change the range in order to accommodate the notes range of the selected instrument or human voice.