Audible Magic's Broad Spectrum: detecting transformed audio

Speeding up...

Social media creators and DJs love to put their own spin on released recordings, and one of the simplest ways is to speed up a track.  Speeding up turns a slow tune into an uptempo dance number, and faster music hits the hook or chorus more quickly.  The current trend on TikTok, where all pop songs seem to exist only in their sped-up versions, has caused record labels and artists across the spectrum to release official speed ups to capitalize on this phenomenon†, from Benson Boon's Beautiful Things, Iñigo Quintero's Si No Estás, and Tate McRae's Greedy, to Lizzy McAlpine's ceilings, which achieved hit status almost entirely due to the unofficial and official sped-up version on TikTok:

and slowing down...

But altering recordings is not new. In the early days of hip hop, DJ Screw and others reversed the above, slowing down tempi to 60-70 beats per minute to create a mellow, bass-and-lyric-heavy grooving laid-back version of what was normally uptempo music. In the 2000s, Nightcore did the opposite with Eurodance, speeding the tempo up to 160-180 beats per minute, chipmunking the vocals into a happy hardcore style of club music. And DJs as a matter of course beat and pitch-match tracks to keep the energy level or to avoid a jarring change of key.  The ability to make these alterations has been democratized by the availability of easy-to-use tools, meaning that anyone with a phone or a computer can produce altered recordings to suit any creative impulse.

and changing the key

That being said, sometimes alterations are done for completely pedestrian reasons. Since at least the 1950s, radio stations have played music faster to fit in more discs per hour and also more commercials and, more recently, uploaders who wanted to bypass content ID systems have been tempted to change the sound just enough that it isn't noticeable to the average listener, but to get it past the automatic filters.  Or, in this case of this Weezer track, pitch shifting up a semitone so that guitarists don't have to retune to play along:

The solution: Broad Spectrum

But in all these cases everyone wants correct attribution and, especially where there are royalties due, for the money to go to the proper artists. Audible Magic's standard Audio ID system was designed from the beginning to easily handle pitch shifts and time scalings in the range of a few percent, in addition to resistance to ambient noise, EQ and other channel effects.  To identify audio that has been altered beyond that - including modifications far beyond what we see in the wild - customers use our Broad Spectrum service.

Designed to tackle the complex issue of manipulated music, Audible Magic's Broad Spectrum is a significant advance in content identification technology. Unlike most Audio Content Recognition (ACR) systems, Broad Spectrum employs an innovative approach to detect alterations.  It gives platforms the confidence that they will be able to identify and attribute content correctly, and also ensures rights holders' content is treated according to their license agreements.

While monitoring what is identified by our system, we see that as much as 50% of the music on UGC platforms is transformed in pitch and/or tempo.  While small alterations are more common, a significant number are altered by 20% or more.  The current trend at TikTok and other platforms is clear in the data: about 4x more of those with larger alterations are sped up vs slowed down.  And changes to pitch alone, while they occur, do not occur as often as playing the music faster or slower, either with or without changes to pitch.

For more than 20 years, Audible Magic has provided B2B solutions in content identification (both music and TV/Film), music catalog fulfillment, and rights administration. Audible Magic powers billions of monthly transactions to serve customers all around the world. Its music identification services are used to help reduce the number of DMCA takedown notices and administer licenses for user generated content (UGC). Broad Spectrum is one of many technological innovations we have pioneered. Contact us to learn more.

– Erling Wold, Chief Scientist and Technologist

† more examples:

https://open.spotify.com/playlist/4sQRT2zDzaMk92Fw75TZHn

https://open.spotify.com/playlist/37i9dQZF1DX0h2LvJ7ZJ15

by Erling Wold