strain after (something)
To struggle intensely to produce or achieve something. The singer was straining after a high note that was clearly out of her range. I could see his feeble brain straining after an acceptable excuse as to why he was so late. The poet long strained after a kind of mythic ideal of his home country, steeped in the folklores of his and several other nations.
strain after something
[for a singer] to work very hard to reach a very high or a very low note. Don't strain after the note. Let it come naturally, like a cooling breeze. She was straining after each note as if it hurt her to sing, which it probably did.