Disclaimer: Some of these tidbits are things I've heard or read over the years, and the source of the info is lost to me now. So, I hope I'm remembering correctly! The rest are more recent discoveries, and the source is mentioned when possible.
***Fur Elise is one of the most famous and beloved classical piano pieces. Beethoven wrote it in 1810, by which time he was mostly deaf. Beethoven became deaf over a period of about 20 years. He kept it a secret for as long as he could. There is no definitive answer as to the cause of his deafness, but I once read that he may have had an ear infection that could have been easily cured with today's antibiotics. Beethoven continued to write music even after he was totally deaf. Here is a link to an article about the deafness. http://www.lvbeethoven.com/Bio/BiographyDeafness.html
****Bill Evans was the great jazz pianist who lived from 1929-1980. He was considered to be a lyrical player; not super-fast with the certain quality that some people call nervouse in describing jazz. What an intelligent musician! In a recorded interview, Mr. Evans said "It's better to play one song for 24 hours than to play 24 songs in an hour." He was talking about taking the time to become excellent. He was saying that many people just like to get a rough proficiency at whatever task they're involved in. But the people who get really good stay on it until they've mastered every detail. That's how they become excellent, by mastering the details. It's best to learn a song inside and out. Playing it over and over and hammering away at the details leads to mastery. Rushing through a lot of material in a general way only leads to moderately interesting playing. If you're going to spend time practicing, you might as well create excellence. Take time and be thorough. Some people consider that approach to be tedious, but I believe it's where the real satisfaction lies. It's like getting inside of the song. You know you're in a different world when you can allow that depth of connection. When we learn a song deeply, it becomes like a friend. We're inside the music. We love it. Plus it sounds great if we do it that way. People sit up and start listening.
****Jim Morrison of The Doors was so insecure about singing in front of other people that when the band first started performing he sang with his back to the audience.
****Glenn Gould, the famous classical pianist who specialized in playing Bach, had a great dislike of performing in public. He said "I despise audiences. I think they are a form of evil." At a certain point he stopped performing in public, and instead broadcast on the radio from his home.
****John Coltrane, the great jazz tenor sax player, practiced about 15 hours a day. When he was recording in the studio, he would arrive 2 hours early to warm up by playing scales. When he was on break at gigs in clubs, he would go in the back and practice his improv patterns.
****Amazing Grace is the most-recorded song of all time. It exploded in popularity after Judy Collins, the pop/folk singer, recorded it in 1970.