MuseScore is an open source cross platform music notation program that has a lot of very good features. Simple to operate, notes are entered on a virtual note sheet with your mouse, MIDI or keyboard. There are an unlimited number of staves and up to four voices per staff, making it very versatile. It also features a note editing input that is much like step-time note entry that found on premium commercial music editing software. Its wizards make it easy to set up and files are opened by a simple double click of the mouse