Impressioni di settembre

Mussida wrote the music in spring 1971. The publisher Mariano Rapetti, a Numero Uno partner, asked his son Giulio Rapetti, known as Mogol, to help Pagani with the words, and they met at the Rapetti estate in Brianza; Pagani saw Mogol's simpler, direct text as the key to its pop appeal. Mussida's account, via Il Post, is that the song came all at once, like a gift. A single recorded at Sax Record in October 1971 with "La carrozza di Hans" on the B-side reached number 10 by Il Post's count; the band then asked Numero Uno to withdraw it and recorded the album version in January 1972. Peter Sinfield wrote English lyrics as "The World Became the World" in 1974 (4:47). It is described by the group and by Il Post's account as a hymn to freedom, happiness and joy.

It is considered the first Italian song with a Moog synthesizer. The band met the instrument importer Signor Monzino at a 1971 fair; he had a prototype portable Moog, they could not afford it, and he let them have it on a promise to sell at least ten, though the Italian Wikipedia says lent and the English says Minimoog. Auralcrave notes it is PFM's first song without a sung chorus, the chorus phrase being played instrumentally in E Dorian with a characteristic major sixth, and that the band had heard the Moog's sound on Emerson, Lake and Palmer's "Lucky Man". A 1972 RAI clip shows them presenting the instrument.

Covers include Franco Battiato, Marlene Kuntz, Angela Baraldi, Gigi D'Agostino, Francesco Renga live, Ezio Bosso as an instrumental, Antonella Ruggiero (2018) and Connie Talbot in English. Panorama listed it among the fifty most beautiful Italian songs. It appears live on 10 Anni Live 1971-1981 and Live in Japan 2002 and as a classical version on PFM in Classic (2013); the English Wikipedia says it is still regularly performed. We could not get a setlist.fm count, and could not tell which version our upload is.