Following the impromptu recording sessions in Austin, Texas Foo Fighters returned home to California where they had just two further live performances left on the United States leg of the Sonic Highways tour. After that, there was a short break in the band's calendar before they were due to head to Europe for a series of shows starting in early November. Before that, the band decided to head into Studio 606. Whilst they were mostly happy with the work they’d completed in Austin, one song, ‘Fuck Around’, was not going to make the cut for the free EP they had planned.
Wanting to keep the release at five songs, the band got to work at their studio from October 20th to 23rd. Just one song is known to have been recorded, another acoustic song to replace the slow-tempo ‘Fuck Around’. The band recorded the new song, ‘Iron Rooster’, predominantly live in the main room at 606 with overdubs then added afterward. In the initial live performance Grohl played an acoustic guitar but also added some clean electric overdubs, as well as playing the piano. He also experimented with a finger slider device on his electric, to generate some of the deep vibrato sounds on the track.
As the band had been globetrotting since its installation this would be the first song to be recorded by the band on the Neve 8028 recording console and given a release, the new song added alongside four from Hotel Saint Cecilia and released as the Saint Cecilia EP in November 2015.