Google is now displaying music lyrics at the top of its search results pages when you search for “song name” plus “lyrics” on Google – a move that may reduce the number of visits to music lyrics sites that now rank highly in Google Search, like azlyrics.com or songlyrics.com, for example. The move follows a change that Microsoft’s Bing made earlier this year, when it added a feature that also saw song lyrics returned above the search results as part of Microsoft’s efforts to compete with Google’s “Knowledge Graph.”

With Knowledge Graph, Google has been steadily enhancing its search results pages for years with data gathered from a number of sources, including Wikipedia, the World CIA Factbook, Freebase, Google Books, online event listings, other commercial data sets and structured data from the web.

With the addition of song lyrics results to Knowledge Graph, Google is just showing longer snippets of the lyrics with a link that points to Google Play for the “full lyrics.” Or in other words, it’s a case of Google promoting its own content above search results pointing to third-party websites.

The change was first spotted by the SEO Roundtable blog, which noticed a posting about this on Google+. We’ve asked Google to confirm when exactly the addition went live, but it may be difficult to get a timely response due to the holidays.

We understand, though, that Google was beta testing this lyrics-finding feature a few months ago, but the full rollout appears to have occurred just a few days ago. (Update: it rolled out last week for U.S. English users, we’ve learned.)

However, in testing, we found that only some searches yielded the song lyrics, while others – including those for popular or classic songs – did not. That could imply that Google is working with a limited lyrics database for right now. It also means that Google is not simply scraping the content from top lyrics websites in order to show lyrics – if it was, it wouldn’t be coming up short.

The ability for web searchers to quickly gain access to song lyrics without having to click through on what are often ad-infested lyrics websites will have a significant impact on this industry, which today heavily relies on SEO techniques in order to get their sites to the top of Google’s search results and drive traffic.

Explains Darryl Ballantyne, CEO at LyricFind, a company that licenses lyrics to third parties like Pandora, SoundHound, Shazam and others, this change will have a large enough impact that some lyric web sites built mainly on SEO traffic will go away. “However, many sites also build community around the lyrics, which Google won’t replace,” he adds. “Sites like SongMeanings and MetroLyrics are more than just SEO farms; I expect they’ll continue to post impressive traffic numbers.”

This is not the first time Google has flexed its muscles with regards to lyrics search. Around a year ago, it penalized a site “growth hacking” its way up the search results page when it discovered that the lyrics and annotations site Rap Genius was using a variety of linking schemes and shady deals to boost their visibility. Google de-ranked the startup, which in its “apology” statement, used the opportunity to lambast others in the industry for doing much of the same thing when it came to dirty deals and link schemes.

Update: A Google spokesperson confirmed the release of the lyrics search feature, saying (yes, seriously):