"Se Telefonando" is a song performed by the Italian singer Mina, released in May 1966. The music was composed, orchestrated and conducted by Ennio Morricone to Italian lyrics by Di Chiara and Costanzo. (Reportedly Costanzo only contributed one word, in editing a previous version of a verse, to avoid censorship). The song was written for a radio broadcast, called "Aria condizionata".

Can we draw the following conclusion?
Morricone declined other songs to work on this one
It's impossible to say