Hookpad, instaComposer, Midi Madness, Cthulhu, Orb Producer Suite, Instachord, Sharp11, Odesi, Automated Composing System, Waveform, AudioCipher, Orb Composer S, Helio Workstation, Chord Composer, ChordPolyPad, AutoTheory, Arpado, Liquid Music, Harmony Improvisator, Harmony Builder, Synfire, Chordjam, Liquid Notes, ChordMaps2, Obscurium, ITVL are some alternatives to RapidComposer.