Not bell ringing - change ringing. Most places they play a tune on them; our ringers work out mathematical permutations instead.
Edit: ...and I should add: Sayers was quite reactionary, preternaturally English, and writing in the 1930s, so I wouldn't be at all surprised if it wasn't true that change ringing was uniquely English.
… and writing a detective story rather than a non-fiction book.
The reality is that someone writing in Harper's in 2025 and using a Dorothy L. Sayers Peter Wimsey story from 1934 as a supporting source is presenting a hopelessly outdated and fictional picture of the world and is going to come up for starters against the Australia and New Zealand Association of Bellringers, founded in 1962.
That link (like the Wikipedia article) is talking about the mechanism by which the bell is rung, not what is rung out on them i.e. they are not ringing the changes.
It's got compositions on the page, a link to a PDF with compositions in it and a link to the Veronese ringing association which has many more examples - if you can read Italian.
Edit: ...and I should add: Sayers was quite reactionary, preternaturally English, and writing in the 1930s, so I wouldn't be at all surprised if it wasn't true that change ringing was uniquely English.