The Book of Common Prayer is the basis of the service, although the prayers of intercession are in modern language and concentrate on contemporary events and situations.
Three hymns are sung of a traditional kind, even where, as occasionally, the words are of 20th or 21st century origin. The choir generally sings a short anthem, giving worshippers a time to reflect – and likewise there is quiet organ music before the service begins.
The psalms are currently sung from the Parish Psalter, but shortly we shall start using The Wessex Psalter, which has exactly the same words but more up-to-date pointing.
There is a sermon (of only moderate length) which refers to one or more of the bible readings, explaining their meaning and/or relating them to the experiences of people today.
Both choir and congregation are interested in welcoming new people. Why not come along one Sunday evening? (However, note that Evensong is not sung on the last Sunday of a month and is occasionally replaced by other services.)
You might want to give it a try, for example, if you used to attend and haven’t been for a while. Or perhaps your own church no longer offers Evensong but you continue to value it?