OtoTheory vs SongEngine

OtoTheory is a chord progression builder and music theory companion for guitar, bass, and keyboard players, songwriters, and DAW users. Its iOS app can identify chords, key, and song sections from imported audio or an on-device guitar or piano recording. Users can paste progressions from ChatGPT, Claude, or Gemini for Roman numeral analysis and playback with grooves. The app lists 19 groove patterns and more than 50 progression presets; OtoTheory AI suggests chords using musical feel, theory, and emotion. Pro exports MIDI in Groove, Groove + Theory, or Chords Only modes, including BPM, section markers, and chord names. The maker says those exports can be used with Logic Pro, Cubase, Ableton, and other DAWs. OtoTheory is available on iOS and the web, but the web version has fewer features and Pro is iOS-only. The free iOS plan allows three local sketch saves and excludes MIDI and audio export. Pro is listed from $5.99/mo; its annual plan is $49.99/year, and Lifetime costs $99.99 once.

SongEngine creates chord progressions and generates matching basslines, phrases, and melodies. Users can make chords with Chord Pads, import MIDI progressions, or generate progressions in the plug-in. Its free core includes 60+ presets for basslines, arpeggios, phrases, and melodies. Live Mode turns MIDI chords sent from a keyboard or DAW into new MIDI phrases in real time. Generated parts can be dragged into a DAW as standard MIDI files; an optional MassExporter can write hundreds of phrases to a computer folder. SongEngine runs as a VST2, VST3, or AU plug-in and needs a compatible host such as FL Studio or Ableton Live. It supports 64-bit Windows 7, 8, 10, and 11, and macOS 10.13 or later on 64-bit Intel or Apple Silicon processors. There is no official Linux build, though the manual says users have reported using Wine. The maker says its algorithms were crafted by human musicians, not AI, and generated MIDI files may be used in commercial releases.