The best ones are in the evening (which you have to pay for), but there also plenty of free ones which they hold at lunchtime a couple of times each week. They usually start at 1 PM, so it's a nice way to rest your feet if you've been pounding the pavement all morning. They've got a big cafe in the Crypt as well, where you can treat yourself to a cup of tea afterwards.
The free concerts can be anything from solo pianists to string quartets, and frequently include a vocalist or choral group -- it's all top quality stuff, and well worth a visit. Check out their website to see exactly who's playing. They usually perform works by the likes of Mozart, Handel, Bach and Vivaldi.
Craig has never been to one of these classical concerts, but he has written a review of St Martin in the Fields church. You might like to give it a quick read before you go, to see what they church is like inside.
There are plenty of other attractions within a short walk of the church. After you've rested up maybe you can pop in to the National Gallery next door? Or have a walk down Whitehall to see Number 10 Downing Street, Big Ben and the Houses of Parliament.
Craig’s review of St. Martin-in-the-Fields – “St. Martin-in-the-Fields is famous for helping out the homeless, and whenever you come in here you'll find a few of them kipping in the pews. There are two guys in here at the moment, gently resting their heads against the stone cold columns. The rain is knocking on the window and they've still got their hoods zipped up. I suppose when you're homeless you expect it to… continued”
Guided tour of the Royal Albert Hall – Every day – This guided tour of the Royal Albert Hall will take you inside one of the balcony boxes for a fantastic view of the famous auditorium.
Bach to Baby, at the Queen’s Gallery – 26 Nov and 17 Dec 2018 – Take your baby to the Queen's Gallery for an informal classical concert and see the Russia Royalty & the Romanovs exhibition
The Nutcracker — at the British Museum – 3, 6 and 8 Dec 2018 – Ballet Central will be putting on a very special performance of The Nutcracker inside the Great Hall at the British Museum
Handel’s Messiah at St Paul’s Cathedral – 6 Dec 2018 – Enjoy a performance of Handel's Messiah by the Cathedral Choir and the City of London Sinfonia at St Pauls Cathedral
Shostakovich, Richard Strauss and Alban Berg – 7 Dec 2018 – The BBC Symphony Orchestra will be performing some works by Shostakovich, Richard Strauss and Alban Berg at Barbican Hall.
Carols by Candlelight at the Tower of London – 8 Dec 2018 – Enjoy a Christmas carol concert inside the candlelit Chapel Royal of St Peter ad Vincula at the Tower of London.
Carols by candlelight, and full 18th-century costume – 12 Dec 2018 – 'Carols by Candlelight' will include your favourite Christmas carols performed in a candlelit setting and full 18th-century costume.
Here are some more free events in London if you want a cheap day out
If you enjoy St. Martin-in-the-Fields then you might like to visit National Gallery (you can walk it in less than 2 mins), National Portrait Gallery (you can walk it in less than 2 mins) and Trafalgar Square (you can walk it in less than 2 mins)
Disclaimer: Event details can change at short notice and you should reconfirm everything before making plans