Today I'm showing the world a project that's actually been kinda near and dear to my heart for quite a while. I've had a few friends using it and got some positive feedback, and as of last week I put the finishing touches on some backend improvements that should hopefully keep it up and running for a while, so here goes:
I've been a member of the website last.fm since 2004, when it was still called Audioscrobbler. As of this writing I've "scrobbled" over 110,000 plays of various songs from various audio-listening applications and services, so it knows when I listened to them and in aggregate what songs, albums, and bands I've listened to the most. That's a LOT of data about me just kind of sitting there, and while I have sometimes used tools near the end of the calendar year that will show you your listening habits for the year or even just browsed last.fm's web interface to check out my listening habits, I don't have anything making regular use of that information, which I still submit to them pretty faithfully through iTunes and Rdio.
So that's why I built Backtracks, an email service that sends you a weekly email to let you know what you were listening to at this time 1, 2, 3... or however many years back you have history for. If you have listening history logged in last.fm during this calendar week some years in the past, Backtracks will send you a quick email letting you see which albums, songs, and artists were among your most played during that time.
I still hope in the future that I'll be able to add direct integration with services like Rdio and Spotify, but their APIs currently don't allow access to historical listening data like last.fm does. If you work there or know someone who does, you should bug them about it! I'd love to support services that people are already using since I know last.fm is sort of a niche thing.
My music listening habits tend to be very seasonal—I listen to Jason Molina and the bands he led in the fall every year, for example, and that's a big part of establishing the feeling of each season for me. Music is really important to me and for those of you who use last.fm faithfully I hope that Backtracks will be an email you look forward to getting as well.