All pictures taken from Google public domain or provided by Google Sites.
Other:
https://unblast.com/10-free-space-background-images-jpg/
https://www.pexels.com/photo/music-sheet-page-210804/
https://wallpapers.com/wallpapers/space-aesthetic-constellations-of-stars-9yx4c2awj2x3n30w.html
https://www.universetoday.com/145898/how-do-you-weigh-the-universe/
https://depositphotos.com/photo/sheet-music-64851765.html
https://en.nureyon.com/treble_clef-1?pattern=60