百囀千聲隨意移， Chirping and flying freely are the thrushes

山花紅紫樹高低。on the colorful flowers among different branches.

始知鎖向金籠聽， Even locked in the cages of gold,

不及林間自在啼。 They wont sing mellifluously as in woods.

PS. Attached is the version of DeepSeek:

Hundreds of trills freely drift with wings in flight,
Amidst red-purple blooms on branches high and low.
Now I know - when caged in gilded bars so bright,
Their song wont flow as wild in woods we know.