Rather than playing tunes, bellringers ring 'methods', which consist of a long sequence of ‘changes’. The bells are first ‘raised’ into their mouth-up position – quite a laborious business that you may see at the start of a ringing session. Then, after a short rest, the ringers will start off in ‘rounds’, which is when the bells sound in a simple descending scale, one after the other in sequence.
The bellringers will be aiming for evenly spaced notes, with just a slight pause after every bell has sounded twice. For example, with six bells you will hear six notes, another six notes, and a short a pause.
After a few descending scales are rung in this way, the real ringing will start. This may be ‘call-changes’, in which one of the ringers, the conductor, will call for selected bells to change places in the order of sounding. Or on the instruction of the conductor, the ringers begin to change the order of sounding according to a pre-arranged pattern called a ‘method’.
These ‘methods’ have to be memorised, at first simple ones, then more and more complex. In any method the order of bells is constantly changing, and is usually not repeated until all the possible orders have been rung.
With four bells there are 4 x 3 x 2 x 1 = 24 different orders (or ‘permutations’, if you’re more comfortable with a mathematical definition) before a sequence has to be repeated (sequences like 1234, 2143, 2413, 4231, etc.). With six bells there are 720 orders, with eight bells there are 40,320 different orders, and to ring them all takes about 28 hours (and it has been done!). Churches with ten or even twelve bells are not uncommon. We'll leave you to calculate the number of permutations ;-)
Each order is called a ‘change’ – which is why we talk of “ringing the changes”. 5000 (or more) changes is referred to as a ‘peal’, which takes about three hours to ring. Commemorative peal-boards on the ringing room walls record notable peals.