Musescore is absolutely the best FREE program for writing music. It is only passed by FINALE – considered a professional level – but it is paid.
It allows for fast and easy note entry on a virtual note sheet. It has an integrated sequencer to allow for immediate playback of the score. MuseScore can import and export MusicXML and standard Midi files.
MuseScore is available in more than 40 languages and is rapidly becoming the leading free music notation software and often praised as a cost effective alternative for expensive software.
Simple and essential program that does its job perfectly. Originally created for Linux, it has the main tools.
Imports and exports gp3,gp4 and gp5 files
Frescobaldi is a LilyPond sheet music text editor. It aims to be powerful, yet lightweight and easy to use. Frescobaldi is Free Software, freely available under the General Public License.
Powerful text editor with syntax highlighting and automatic completion
Music view with advanced Point & Click
Midi player to proof-listen LilyPond-generated MIDI files
Midi capturing to enter music
Powerful Score Wizard to quickly setup a music score
This software being of professional level I recommend it to those who really require all the tools and functions, because obviously they are paid and it is not cheap …
Finale is proprietary scorewriting software developed by MakeMusic, Inc. It displays music primarily in music notation and allows for multiple tracks and very specific tweaking of instrument sounds for each track.