- IMSLP: IMSLP is a vast online library that offers free public domain sheet music. You can find works by Andre Gagnon on IMSLP, including some piano pieces.
- Musipedia: Musipedia is another website with a collection of free public domain sheet music. It also has a section dedicated to Andre Gagnon's compositions.
- Gagnon's Website: Andre Gagnon has a personal website where he provides some of his piano sheet music for free download, such as his popular piece "Sonate No. 1."
- Other Websites and Blogs: There are numerous websites and blogs dedicated to classical music and sheet music sharing where you might be able to find Andre Gagnon's piano sheet music.
- Local Libraries: Public libraries often have collections of sheet music that you can borrow or sometimes find in digital formats.