Interview: LiquidRain of is a video game soundtrack streaming site where the listeners get to steer. While the current song is playing, three future potentials are presented in a voting table. Then, based on votes from all current listeners, the next song is slotted for play. Additionally, songs can be rated, and these ratings then affect how frequently the song is subsequently queued.

Once a song has been played, it goes Off Air for a variable amount of time — determined by its overall rating — preventing repetition and giving more of the playlist an opportunity for exposure.

I spoke with LiquidRain, owner and developer of Rainwave, about the site, stats, and songs.

Who’s behind How did the site come to be?

I’m the sole programmer and designer behind Rainwave and did the majority (as of today) of the playlist. Going forward, Vyzov, a member of the community, is managing the playlist. The site came to be when I was looking at long-standing radio site GamingFM and saw their request feature. I was wondering why their requesting was so mysterious and didn’t spell out exactly how their system worked, and that’s when I got the idea of creating a radio site that had instant feedback. From there the ideas evolved. I kept it between friends, working on it until it evolved to Rainwave, when I considered it good enough for people to use.

The voting and statistics gathering are the calling cards of Rainwave. How did they evolve, and how does the system work?

Rainwave first started out as just the voting mechanism – the immediate feedback GamingFM lacked. The same three song selection system was in place from the very beginning. It was sloppy though, and forced you to make your vote 30 seconds before the song ended due to being generally dumb, and did a complete page re-load instead of the nice self-updating you get today. Slowly but surely I kept adding features: ratings, then ratings affecting song frequency, making the page update nicely, and using a tabbed interface for the playlist and song history. I kept evolving the site itself to function better; it became smarter and used the windowing system you see now, instead of tabs, and became a more cohesive and simplified UI while still retaining all the features. The last major feature was requests, after that I just kept adding layers of statistics to the site and made the site snappier and easier to use and read as time went on.

The whole system is dependant on a C++ backend custom-written from scratch by myself, a PHP-driven website, and a MySQL database (though I wish I went with PostgreSQL). The backend’s work is triggered each time a song changes, and the site is synchronized with that. The rest is all in the programming.

Why Ogg Vorbis for the stream?

Simple: More bang for your buck. An 80kbps Vorbis stream sounds better than a 128kbps MP3 stream.

Now that you’ve been tracking song ratings and stats over time, have any surprises or interesting trends appeared?

Yep. Ratings generally keep going down as more people come to the site. The average rating of all songs and albums has been falling as time has gone on. A few ratings for some albums surprised me: I thought for sure that Parappa would have been a hit with the audience, but I was wrong. It was averaging a 2.2 rating when I pulled it. Other experiments with music genres had expected results: both Quake games bombed in ratings, and so did Wipeout.

There are some interesting anomalies in people’s stats too: Very active users who’ve never cast a rating but vote frequently, people who vote a lot and never request, people who listen a ton and never vote or rate, everyone seems to use it differently.

How often does the playlist change? Is there deliberate focus on style or period with the track selection?

The style is laid out in the Requests section of the forums, which basically boils down to some style choices I made that are in line with my own preferences for video game music. There are some exceptions of course:
1. Minimal amount of lyrical songs
2. No chiptunes
3. Upbeat or energetic

Playlist updates happen according to Vyzov’s schedule. He handles the playlist. (though I can certainly still do any updates as well) There’s no regular schedule to it though, I can tell you that, it’s all up to how much time he has to work on Rainwave and how many albums he thinks are good enough to go on the air. It’s a time intensive process since we go over ever track of the album and pick the ones we think should go up.

Why the ban on chiptunes?

I could probably list a bunch of reasons such as keeping tons of overplayed NES chiptunes off the station, them being done to death, plenty of other places to find them, wanting a more modern sound to the radio (really kind of a lie considering the SNES and Genesis content), but really it’s a personal preference of mine.  I’m just not a big fan of chiptunes.

I’ve noticed a high proportion of cult classic and other titles relatively unknown outside the hardcore audience. Does this reflect your own gaming history?

Sure does. There’s plenty on there that are recommended by my own friends or listeners that I’ve never heard that I thought were excellent soundtracks, as well as a few indie games (from bigger names such as Aquaria‘s gorgeous soundtrack to lesser known ones like Booster Logic‘s catchy pair of tunes). I’m all for introducing myself and others to new game music – and if it gets you to check out a game you’ve never heard before I consider that a job well done. :)

Petroglyph recently gave you their blessing to use the Universe at War soundtrack. Have you heard from other developers or publishers concerning the use of their soundtracks?

Unfortunately not. I’d love to hear from other developers!

What’s next for you? Any plans to apply the rainwave system to other genres?

For Rainwave: I have many plans for exposing more of Rainwave’s statistics to users and adding a lot of small touches to the user interface that people are requesting. Before that, I just wrapped up integrating all of Ormgas’ users to Rainwave. Ormgas is the main Overclocked Remix streaming radio station, sort of a sister to their Last.FM community. Ormgas will be moving to Rainwave’s software and will be a 2nd stream running on the Rainwave site.


Thanks to LiquidRain for taking part. Check out, tune in to the stream, or say hi in the rainwave forums.

Thirst for more? Watch the Rainwave tutorial video:

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