If you’re a regular Grooveshark user, you might have noticed this week a fairly significant change to the way ads are presented on the website. In fact, if you’re a free user, you’re not going to be able to get any of the jams you’ve saved in the ‘My Music’ tab unless you sit through an entire albeit brief ad now.

I know. Take a breath, exhale, and keep reading. It’s really not as bad as it sounds. Really.

When you log in to your account and select some music to listen to, you’re likely to encounter a window titled “Keep the music going.” Basically, this window offers a selection of membership options that will determine how you pay for the service: via ad exposure or by signing up for a small monthly fee.

Users have five options with this window: sign up for a paid membership in the amount of $2, $4, $6, or $9 per month in order to have unlimited access to your music; or continue on without becoming a paid member. If you choose the latter option, you’ll be required to watch one short advertisement per every four hours of music you listen to.

Should you choose to continue without paying anything, you’ll be prompted to sit through the aforementioned video which could either be a music video from a featured artist or a video from one of Grooveshark’s ad partners. Whichever you get, it’s imperative that you sit through it – if you try to skip through the video, you’ll see the following message:

After you make it through the video, though, you’re free and clear for the next four hours to listen to your heart’s content. Got that? Four hours for no more than 60 seconds of your time. You probably spend more time exposed to billboards on your commute to work than it takes for you to get through this ad.

The amount of ads encountered on Grooveshark up to this point has been rather unobtrusive, or at least as unobtrusive as possible. This current pop-up, which usually only displays an ad for 15 to 60 seconds, is hardly an obstruction. Every other online service uses ads like this and many YouTube videos are prompted by an ad at the beginning. People obviously don’t mind all that much or else they wouldn’t continue to push Google/YouTube to the top of comScore’s most popular online video sites. Besides, if you watched YouTube videos for a solid four hours, you’d end up watching loads more advertisements on the site than the one-per-four hours you watch on Grooveshark. Hell, you’d see more ads in about 20 minutes of watching television.

Anyways.

The videos currently only show up based on an algorithm that distinguishes the “power users” of Grooveshark and, as mentioned, some of these videos might just be music videos from other musicians. “By involving our most engaged users, these videos become a unique and powerful promotional tool for artists, labels, producers, brands, everyone involved,” said Alex Hoffman, Grooveshark’s Director of Artist Services. He added that, over time, Grooveshark will be implementing more ways to make the website “as personal, relevant, and enjoyable as possible.”

I know, it’s the costume de rigueur for internet users to dress themselves up into fits of puerile impatience whenever a free online service makes a change to its site, but… really? It wouldn’t kill you to give credit for a service you enjoy. And even if you don’t, it’s still not costing you anything.