I can't believe no one has posted here yet!
I am a professional pianist, piano teacher and dance accompanist.
I am not independently wealthy and have to choose my score purchases carefully. (I own the Urtext Beethoven sonatas, the Well-Tempered Klavier, complete Schubert sonatas, Rhapsody in Blue and maybe a dozen others.) However, my life involves playing a lot of different pieces. Much of my repertoire is public-domain composers.
BEFORE IMSLP
1. I was mostly limited in my teaching to what I owned.
2. My personal library dictated my working pieces on the piano, not the other way around.
3. I once spent FIVE HOURS in the Mount Holyoke College music library searching for waltzes for piano in a particular tempo, for ballet class. I found about 10 waltzes.
4. Ballet scores were the Holy Grail. I could never find them, and even when I could, they'd be very expensive.
WITH IMSLP
1. I found the perfect Mozart piece for a student in 5 minutes on IMSLP in between lessons.
2. I have learned at least 40 classical performance pieces from IMSLP scores, for free.
3. I have a collection of over 500 pieces for ballet class repertoire, most downloaded from IMSLP. They magically weigh less than 4lbs because I carry my laptop to class now instead of a bunch of paper.
4. I can use the Category Walker to find waltzes in less than a minute.
5. I own, for free, the scores to Don Quixote, Sleeping Beauty, Nutcracker, Raymonda, Sylvia, both versions of Swan Lake, and some oddities like La Pavilion d'Armide.
6. I can totally impress the dance teachers I work for by downloading and performing pretty much any pre-1923 music they ask for, right there during class.
I love IMSLP!
