Classic Mendelssohn
The classical music archives is the largest collection of complete classical music files (midi and mp3) on the web. most composers are represented. a search engine is included.
http://www.classicalarchives.com/mendelssohn.html
Classicals
The classical net web site offers a comprehensive collection of information and news on classical music subjects including articles and cd/sacd/dvd reviews, composers and their music, the basic repertoire, recommended classical music recordings and a cd buying guide.
http://www.classical.net/music/comp.lst/mendelssohn.html