Isolating The Beatles with AI : So easy anyone can do it!
The release of The Beatles final song Now & Then has brought attention back to the power of using AI in music production. But while movies like Star Wars are reviving dead actors, instead of creating a computer-generated John Lennon, the technology on Now & Then was used to isolate individual instruments from an old cassette so they could be cleaned, remastered, and presented sounding almost good as new.
Different techniques to do this have been around for decades in one form or another, but now it’s become so advanced and accessible anyone can do it at home, and eager fans are sharing their work online.
Previous techniques to isolate music included phasing, where you play a song at the same time as an instrumental version. This removes the identical parts on both songs, so you should be left with just the vocals, but depending on how the song was mixed it didn’t always work. Another technique was to remove certain frequencies using EQ allowing you to isolate lower frequencies to end up with just the drums and bass. But even this wasn’t perfect. Case in point, listen to this video uploaded to YouTube five years ago of just the bass parts from The Beatles Abbey Road album. It’s mostly successful, but occasionally you can hear other instruments bleed into the mix.
More recently, the YouTube channel Rock Band Stems have uploaded some very clean isolated Beatles music. These have included isolating select instruments and vocals, all produced using AI tools, with one of the most popular videos featuring just the rhythm section from Rubber Soul. The channel is run by a musician named Vince who began uploading videos in 2020 when COVID-19 shut everything down around the world.
“I started my channel as a hobby. I had discovered the stems from The Beatles : Rock Band video game a few years ago, and was blown away by the whole process that EMI and Harmonix took to create stems out of these recordings. I then discovered channels like DLD2 Music and projects such as The Beatles : Rock Band CDLC, which used modern AI tools to make stems out of songs I loved, and I wanted to do the same! Since 2020, AI tools have become massively popular, so the technology is constantly evolving. I try my best to use the latest and best tools available,” Vince said.
Currently, Vince uses MDX23, which can be tried for free on the MVSEP website. The technology was created for the Music Demixing Challenge sponsored by Sony, Mitsubishi, and Moises, where multiple entrants have competed to create the best technology for separating songs into stems.
To try it for yourself, go to mvsep.com and upload any audio file from your computer. There are several options under separation type, including MDX23 which will separate the instruments and vocals into two seperate files. Registering an account gives you options to create a uncompressed WAV or FLAC file, but unregistered users can still get an MP3. Click ‘Separate’ and the file will go into a queue before you’ll be able to download your separated files.
Although the technology is very good, and can separate most music with surprising accuracy, it makes things easier when there has already been some separation done in the mix, as Vince explained.
“It starts with finding the best mix for a song. I tend to look on the internet for surround mixes, Atmos mixes, or even quadraphonic mixes, and if I can’t find any of those, I’ll use a standard stereo mix. I then feed the separate channels into the AI I use (left/right for example), which is one of the ways to get clearer results. Then I do use a DAW in most case, whether it be Audacity for simpler mixing needs, or Logic Pro when the files need a bit more work.”
Free tools such as MVSEP and Audacity, have made isolating, editing, and even remixing, accessible to almost anyone with a computer and internet access. MVSEP also host several other AI algorithms that each have slightly different benefits, with some better for vocals and others better at isolating drums and bass.
They’re also not the only free website with AI isolating technology. DEMUCS is another favourite, as well as Moisis which has an app for phones or computers too. Paid options also exist, such as web-based LaLaL.ai and AudioShake, or the standalone iZotope RX 10 which has a Music Rebalance option to isolate instruments alongside many other tools for cleaning audio.
It’s not just fans and bedroom producers using AI to create stems, as De La Soul recently announced they used AudioShake to create stems of their stereo masters so they could be remixed into Dolby Atmos. AudioShake has also been used on other commercial projects such as to create a spatial mix of Nina Simone’s debut album Little Girl Blue, and even assisted in dubbing old episodes of Doctor Who into German by removing the English dialogue.
Other than remixing, another motivation for isolating each instrument in a song is to help people wanting to learn to play the music themselves. This might be difficult when a song includes vocals, bass, guitar, synths, and drums all mixed together, so isolating just the instrument you want can help you hear things more clearly, and people have used the videos on Vince’s Rock Band Stems channel for just that.
“I know a lot of people use my stems to learn songs more easily, and I’m very grateful they do. Great covers all over YouTube have credited me for my work and it’s always nice to see my stems in use by anyone,” Vince said.
Additional reading
For those interested in learning more about the technology MVSEP use, they list details of all of their algorithms on their website.
For MDX23, you can also check their GitHub project page for further details on how their technology works.
For details on The Beatles’ Now And Then, they released the short film ‘Now And Then — The Last Beatles Song’ which gives some information on how the song was revived from cassette.
