Sunday's two Proms continued the weekend's focus on youth with their extraordinary line-ups of performers. In the afternoon event some 550 choristers, including the National Youth Choir of Great Britain, took part in the first performance of Bob Chilcott's cantata The Angry Planet. Setting a worthy text by the poet Charles Bennett, Chilcott's 45-minute work employed a retro style to explore the lamentable depredations of man upon the environment in harmonies Vaughan Williams or Herbert Howells might have penned.

More memorable than the material was Chilcott's finely crafted choral writing, even if the one thing the piece never suggested, despite a confident performance by its numerous adult and young participants under David Hill, was anger. More striking was the short opener, Ben Parry's Flame, to words by Garth Bardsley, which employed imaginative techniques to build its small structure to a wonderfully resonant final  chord.

Vast forces were again on the platform for the evening concert, the National Youth Orchestra of Scotland sharing the programme with the BBC Scottish Symphony Orchestra under Donald Runnicles, who achieved not merely immaculate ensemble work but performances of personality and pizzazz. James MacMillan's Fanfare Upon One Note joined warhorses by Wagner and Strauss, all expertly delivered by one or other ensemble, and sometimes both.

Now 84 years old, Thea Musgrave was present to witness the warm welcome accorded her 10-minute Loch Ness – A Postcard from Scotland, lightweight in intention but beautifully imagined orchestrally, with tuba player Ben Thomson embodying the fictive monster.

Earlier, violinist Nicola Benedetti revealed all the lyrical charm of Bruch's Scottish Fantasy, while the two orchestras' joint rendition of Respighi's Pines of Rome provided the final flamboyant roof-raiser.

•Available on iPlayer until next Sunday. If you're at any Prom this summer, tweet your thoughts about it to @guardianmusic using the hashtag #proms and we'll pull what you've got to say into one of our weekly roundups – or leave your comments below.