1. JustinGuitar.com – Hundreds of free guitar lessons with video and audio.
2. DrumLessons.com – The ultimate online resource for drummers of all levels.
3. PlayBassNow.com – Learn to slap that bass.
4. ZebraKeys.com – 50 free piano lessons for various difficulties.
5. PianoPractice.org – A free online PDF on the fundamentals of piano practice.
6. UkuleleUnderground.com – Video tutorials on playing the uke.
7. UkuleleHunt.com – Blog, lessons, ebook, and more on playing the ukulele.
8. ViolinOnline.com – Violin music and instruction for all ages.