A long time ago, when Last.fm started, it had the option to play music similar to two or more artists. You would write the artists separated by a comma and you would get a playlist of artists which were similar. That was really good.

A very VERY long time ago was echo.com. It's hard to find any information about it now. But it was a streaming music site that let you rate the artist, album, and song individually with stars, and it would use those ratings to make recommendations to you. Also as you accumulated listening hours you earned Amazon gift certificates. I wish someone out there remembered them besides me.

If I'm not mistaken, Rdio's engineering team helped build Pandora's on-demand service. I've switched to it from Spotify after using Rdio in the past. Its recommendations feel similar to Rdio's, but the interface is a bit lacking. There aren't general recommendations. Instead, you must build a playlist and then you can add a set of recommended songs to the playlist. Of course, there are also radio stations.

RIP Rdio... I also loved it. It had a great portfolio, the website was not massively heavy and it had a very nice design overall...

I miss Grooveshark.

Don't get me wrong Gooveshark had possibly the best UI of all the streaming services but it was largely successful because all the content was pirated.

I know. I wish they had been able to go legit. As someone who went to UF (for CS) soon after they closed, I missed having a company like that in the area.

Don't forget that semicolon.

I miss their api the most and being able to embed play any song using it.

New music Tuesday on Rdio was like Christmas every week. I loved scrolling through the long list of album covers to see what dropped this week. Sampling interesting stuff as I went along.

RIP Rdio.

Beautiful app. Better social/playlist and collection sharing. The only thing they were late on was downloading content for offline. But that eventually came too. RIP.