Inner Song was first announced on 25 February 2020 alongside a release of the album's lead single, "Melt!".[3] Owens wrote and recorded the album after what she considered to be the hardest three years of her life.[4] Originally, the album was scheduled to be released on 1 May 2020,[5] but due to the COVID-19 pandemic, the release date was pushed back to 28 August 2020.[1] The album's name is borrowed from a 1974 album by Alan Silva.[4]
The single "Corner of My Sky" features vocals from John Cale in both English and Welsh.[6] Owens explained her collaboration with Cale and the inclusion of the Welsh language was a means to connect with her Welsh heritage.[6] Cale noted that his ability to conjure Welsh phrases was a "surprise since I hadn't written in Welsh for decades".[7]
The album also features a cover of the song "Weird Fishes/Arpeggi" from the 2007 Radiohead album In Rainbows.[8]
Some vinyl editions of the album include a hiddenbonus track, titled "My Own", which was released as a Bandcamp exclusive track in March 2021.[9]
The album was released to critical acclaim. At Metacritic, which assigns a normalized rating out of 100 to reviews from mainstream publications, the album received an average score of 84 based on fourteen reviews, indicating "universal acclaim".[29]
Critics praised Owens for her ability to combine multiple genres in a single album. Paul Simpson of AllMusic noted how Owens "flip[s] from downtempodream pop to spacy techno with ease," and compared her multi-genre approach to her debut album, Kelly Lee Owens.[14] Nathan Smith for Pitchfork writes that Owens is able to utilize multiple styles in the album as a result of "her unusual ability to join the physical with the emotional."[8] Writing for NME, Ben Jolley lauded the album as "perfectly-arranged" and described it as "an emotive-yet-euphoric collection that's made for late-night reflection, Kelly Lee Owens has made one of the most beautiful records of the year."[10]
Critics also praised Owens' vocals. Smith writes, "her vocals are as confident and captivating as her beats."[8] Greg Cochrane of Uncut praised the development and use of Owens' voice: "this time, when deployed, it's positioned centrally."[28]