'primary inspiration' is correct and usable in written English.
An example sentence using 'primary inspiration' might be: "The primary inspiration for my designs comes from the natural environment."
But he drew his primary inspiration from his childhood.
Monteverdi, he says, was his primary inspiration when it came to the music.
From WHERE did he draw his primary inspiration when writing "Fahrenheit 451"?
Armitage often speaks of Balanchine in interviews, and I think his "leotard" ballets were the primary inspiration for her choreography.
He made clear that his primary inspiration when it came to dealing with legislators was Bill Clinton, not his father.
During this era all countries were brought into the same orbit, although Italy remained the primary inspiration.
One strand of Mr. Friedman's songwriting owes to Liz Swados, a primary inspiration, and is unrhymed, talky, and streetwise.
The drummer, Linda McDonald points to Iron Maiden's "Maiden Japan," an EP recorded in 1981, as her primary inspiration.
Their primary inspiration, however, stemmed from the Pont-Aven school, which centred on the Post-Impressionist painter Paul Gauguin.
It was never a secret that Johnny Carson's "Tonight Show" was the primary inspiration for "Larry Sanders".
Meanwhile, some of the roughest, rawest blues is serving as the primary inspiration for some of the roughest, rawest and most authentic rock.
