Open Source Apple iPhone Music Composition Apps

MuseScore is a free and open-source music notation software designed for composers, arrangers, educators, and musicians of all levels. It allows users to write, edit, and print professional-quality sheet music with no limitations or subscription fees. MuseScore Studio supports a wide range of instruments and ensembles, from solo piano and guitar to full orchestras and choirs. The software is easy to learn while still offering powerful tools for advanced notation and score layout. With support for MIDI input and formats like MusicXML and MIDI, MuseScore integrates smoothly with other music software and workflows. Built by a global open-source community, MuseScore continues to evolve through active development and community contributions. Support MuseScore at http://musescore.org/en/donate

Modus is an open source, cross-platform C++ library which allows you to handle music from code. This means that you can: * Manage interactive and adaptive music * Use some kind of algorithm to improvise * Represent visually (simulate) musical performances * Select in real time the instruments that are going to play a previously written song * Let the user take part on the performance through any type of interface, by playing an instrument, changing the tempo, choosing the instruments, designing the structure of the song, etc. * Define song structures with metric modulations, accelerandos and ritardandos * Write your own scores, which can then be assigned to instruments to be played * Play along with a pre-recorded song or represent the performance * Everything else that comes into your head