There is a really good set of FAQ entries for PG Music products. Click on Support at the top of this page.

Here's your answer, from the FAQ:

http://www.pgmusic.com/techfaq28.htm#85

A lot of them are remnants from early versions. The two to know are .SGU and .MGU. When you enter only chords, it's .SGU. When you then add a melody, it gets saved as .MGU.


BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.