Which poitic device is used in this '' sings and strain''?

Alliteration - where Words begin with the same letter or sound.

I thinks this comes from Wordsworth's "The Solitary Reaper", where Wordsworth uses Words beginning with "s" throughout the poem -

single, solitary, stop, sings, shady, spring-time,sands, silence, seas, strain, some, sorrow, singing, sickle.

Sadly, some other soul should say what the point of this was - I have no idea.

The folk-rock group Lindisfarne did a similar thing in "Fog On The Tyne" -

Sitting in a sleazy snack bar, sucking sickly sausage rolls. Slippin' down slowly, slippin' down sideways....