A scorewriter, or music notation software , is software used to automate the task of writing and engraving sheet music. A scorewriter is to music notation what a word processor is to written text.All scorewriters allow the user to input, edit and print music notation, to varying degrees of sophistication. They range from programs which can write a simple song, piano piece or guitar tab, to those that can handle the complexities of orchestral music, specialist notations (from early music to avant garde), and high-quality music engraving.

Music is inputted using a mouse or the computer keyboard. Many scorewriters also allow it to be played in from a MIDI keyboard. A few allow printed music to be scanned in using special music OCR software.Most scorewriters also allow the music to be played back via MIDI. This means that scorewriters have a certain amount in common with sequencers (many of which can also write music notation up to a point), though scorewriters are used primarily for writing notation and sequencers primarily for recording and playing back. Hence scorewriters can be used for all types of music, though classical complexity often means that scorewriters are used more for that style. 'Real Book' style lead sheets can be created for jazz musicians.