The phrase "as the strains" is correct and usable in written English.
It can be used in contexts where you are referring to musical strains or themes, often in a poetic or descriptive manner.
Example: "As the strains of the symphony filled the air, the audience was captivated by the beauty of the performance."
Alternatives: "as the melodies" or "as the notes".
Partygoers shot pool as the strains of Mr. Carter's single "Help Me" thumped through the smoky room.
As the strains from the Chipping Norton Silver Band faded away, the writer and comedian Graeme Garden leapt on to the stage.
If women avoid certain paths at one stage in life because those paths are hostile to family life, they forfeit the benefits as well as the strains.
During the seventh-inning stretch last night, the crowd stood as the strains of "God Bless America" wafted through the hazy sky.
4.03pm: The Murrays break back, as the strains of a cover version of Sweet Child O'Mine blare from the speakers in the empty tennis arena.
As the strains of the war mounted, that facade progressively slipped away, revealing the realities of threat and extortion that Iraqis confronted almost every day under Mr. Hussein.
Last night as the strains of the Minute Waltz faded away, Just a Minute chairman Nicholas Parsons introduced the 761st episode of Just a Minute.
As the strains of Haydn's "Farewell Symphony" rose, he said, "And now it is time for my own personal farewell to you, and it is not easy….
As the strains of Rodgers and Hammerstein's You'll Never Walk Alone filled the fetid morning air, I thought of another musical.
It turns the party into a political pantomime horse unfit to govern – and may ultimately force its break-up as the strains of the lived inconsistencies become intolerable.
As the strains of "Pomp and Circumstance" dissolve into the past and the latest batches of college graduates issue forth into the work world, they can expect a warm welcome from the nation's employers.
