Piano 
8 Notes(7)
8notes.com focuses on traditional and classical lessons. They have over 100 free violin pieces in their own collection and hundreds of melodies for traditional violin, pipe and other treble instruments. Each song has a downloadable gif or pdf file and you can also listen to the midi version of the song. You have to [...]
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Learn Piano Online
The free lessons on Learnpianoonline.com are quite good and go through most of the basics and then move on to slightly more complex topics. There are audio files as well which make it a lot easier to follow.
The lessons are laid out fairly well with graphics of the correct hand positions etc.
Visit site: http://www.learnpianoonline.com/
Levels: [...]
Play piano
Playpiano.com mainly focuses on the dvd crash courses that the author sells. You can sign up for some free lessons as well. The site is quite text heavy and a little hard to navigate around, but who know, the lessons might be brilliant.
I would welcome any feedback from anyone who’s tried a lesson from this [...]
Music and you
Musicandyou.com has free and paid lessons. The free lessons are pretty good and include a detailed PDF of the lessons and audio. They focus mainly on blues and jazz piano. The site can be a little bit fiddly to navigate around but there are some good lessons which include an audio description of how to [...]