thanks for the reply, I always liked to give subfire a try but I never are comfortable to enter my server credentials somewhere. (yeah I read all about it.. still

)
anyway, back to the topic... the easiest thing would to mach against plain text files with artist and trackname since you are getting this out of every service. most of them are snippets or workarounds but they all leave me at least with the artist & track information. A tight match shouldn't be a problem, at least for me.. alll my stuff is painfully tagged with picard/mb and exact as possible.
also i have to agree with your sight on spotify and co... therefore I love to have my own.
Here is an example of a exported plain list from allmusic it's actually (%artist - %album - %track), since they don't have any function for this i used some 3rd party code snippet which works pretty well. (
https://gist.github.com/jmiserez/c9a9a0f41e867e5ebb75)
Friska Viljor - In My Sofa I'm Safe - In My Sofa I'm Safe
Will Butler - Anna - Anna
Death Cab for Cutie - Black Sun - Black Sun
Hot Chip - Huarache Lights (Soulwax Remix) - Huarache Lights (Soulwax Remix)
Viet Cong - Viet Cong - Silhouettes
Action Bronson - Baby Blue (feat. Chance the Rapper) - Baby Blue (feat. Chance the Rapper)
Modest Mouse - Strangers to Ourselves - Ansel