In November 2018, Beck posted two short clips on his Instagram of his father conducting a string section, while a tape of Beck's voice sings some new song for them to play over. The above lyrics are what I could make out.
A day later, Beck posted a photo of sheet music to instagram, showing the title of a song called "Roma." It says at the top "arranged by Beck Hansen" and "Orchestra by David Campbell." Beck's caption for the photo explained that he was "recording orchestrations for the film Roma by Alfonso Cuaron."
Neither the song nor orchestrations are in the film Roma, which came out on Netflix in December 2018. It is unknown if the song/orchestrations are one track, or two.
In January 2019, Beck's "inspired by Roma" single came out, a cover of a 1982 song by the band Colourbox. It does not appear to me to be this snippet.
So the question remains: what is this song he put a short clip of on instagram that he was doing along with "orchestrations" and "Tarantula"?