Henry Purcell (1659-1695) was the leading english baroque composer of his time. This aria comes from his opera “Dido and Aeneas”, one of the first english operas, first performed around 1688 by the students at a school for girls in London for whom it was written. It was never again performed in Purcell’s lifetime. In fact it was not played at all between 1700 and 1895 !!
The aria is a very moving, tragic lament by Dido who, after rejecting her lover and forcing him to abandon her, sings this aria announcing her imminent suicide.
Original Aria   Edited Performance Version   Clean Performance Version  Easier Version  Score with Keyboard Accompaniment
And here is an audio file of the accompaniment played on the guitar: