"I'd forgotten we were here," reported my five-year-old niece, stretching. "I thought we were still on the sofa at home." Testament to the comfort of the seats in the Albert Hall, perhaps, but also to the Proms' family-concert programming – for she was emerging not from a cosy slumber, but from the kind of transported experience we all hope for but rarely manage.

This was at the end of the concert, whose second half was a screening of Nick Park's animated film A Matter of Loaf and Death (shown for the first time with a live orchestral soundtrack), with Julian Nott's colourful and intricate score performed by the Aurora Orchestra and Nicholas Collon. But the real headline act was the unveiling of Wallace's new concerto ("in Ee, Lad") at the end of the first half.

Thanks to a video-link to Wallace's dressing room – and the red telephone on the "Semiquaver Time Saver", an enhanced podium complete with baton rest, cake-stand and vacuum-flask chute – we soon learned that finishing touches were still being applied to the concerto. Regular updates interspersed the clever and challenging programme of short pieces and excerpts, which included Copland's Fanfare, Adams's Short Ride and excerpts from Shostakovich's Fourth Symphony, all performed with the orchestra's customary energy and brilliance.

In the end, though, an accident with Wallace's pianomatic meant the magnum opus went up in flames. Luckily, Gromit (aka Poochini) was to hand, penning at breakneck speed his Double Concerto for Violin and Dog in the nick of time. Tasmin Little, after a beautiful performance of Vittorio Monti's Csárdás, gamely returned to help out with the solo part, duetting with Gromit over the video link. Thanks to the combined energies of all concerned, the result was transporting and, needless to say, wonderfully animating.

• Available on iPlayer until 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