The Evensong service is completely free and if you turn up a bit early then you can wile away some time in the crypt downstairs where you can get a sneaky look at Nelson's tomb through the big iron gate (there's a side door round the lefthand side of the steps). They've got a little restaurant and a shop down there as well. Just don't make the same mistake that I did and come out with only thirty minutes to spare, because you'll discover that half of the congregation have already gone in ahead of you.
The priests don't seem to mind the congregation sightseeing for free at St. Paul's because once I was inside I was able to walk around a large part of it without restriction, all the way up to the central dome. You can't walk any further than that though, or up any stairs, but even so, that is still a fair-sized chunk of the cathedral to see for free. When I went to Westminster Abbey last week they kept you cocooned in a little line up the side, but at St. Paul's they don't seem to mind as much.
I'm not a big fan of the seats at St. Paul's because considering the scale and the grandeur of the place you expect to see some proper pews, but they've basically just scattered around a load of wooden school seats. Happily I managed to grab one right at the front which allowed me to see the choir in the quire doing their tune-up, and I swear to God that some of the kids were no more than eight. They still sounded amazing though. Even their tune-up sounded great.
While you're sitting there waiting for the service to start you have to share the space with about a million bazillion tourists still walking around with their audio-guides on. It's not until it gets closer to 5 o'clock that they finally get kicked out of the church, and that's when the choir disappears as well -- out the back for a dress change. Most of the remaining congregation seemed to suddenly disappear at this point as well, so I guess they realised that an actual mass was going to take place and lost interest.
I was all ready for the service to begin now, sitting happily in my seat with a great view of the altar, but I got a nice surprise because somebody ushered about sixty of us into the seats by the quire. (The quire is that set of dark wooden stalls that face each other behind the altar, decked out in lampshades and comfy cushions.) It turned out that the quire was too big for the choir and they had a load of spare seats going, so I ended up sitting in the stall seat reserved for Cadington Major (that was the ancient name chiseled onto the back of the stand).
Once everybody was ready the choir filed back in and started singing their songs whilst the priests paraded in. Everyone was issued with a prayer book and a music sheet but none of us had to sing -- there were no hymns for the audience. The congregation just sat there whilst the choir did all the music. And there was no Holy Communion either. That's the only bit I remember from my youth: queueing up for those little white wafers and having to pass on the wine because I was too young for booze ("but it's not booze, it's blood!").
The service just consisted of prayers, a couple of readings from the Bible and some songs sung by the choir. Fifty minutes later it was all over and we had another quick little look around before dropping a few quid into the offering box.
So how did it compare to the service at Westminster Abbey? If you only have enough time for one then I would definitely choose the Abbey. Not that there's anything wrong with the service at St. Paul's, because it's still definitely worth attending.
But I just prefer Westminster Abbey as a building because St. Paul's is very white and bright inside whereas Westminster Abbey is a lot more intimate, and I just think that a church service is better held in the dark.
Brompton Oratory (catch a tube from St Pauls to South Kensington), Westminster Abbey (St Pauls to Westminster) and Westminster Cathedral (St Pauls to Victoria). There are three more church services that I recommend: the Evensong at Westminster Abbey, choral service at Hampton Court and Sunday service at the Tower of London
If you enjoy St. Paul’s Cathedral then you might like to visit