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”
Britten Sinfonia playing Delius, Mahler and Brahms – 17 Jan 2019 – Sir Mark Elder and the Britten Sinfonia will be performing some classical music by Delius, Mahler and Brahms at Barbican Hall.
BBC SO, playing Beethoven and Schoenberg – 18 Jan 2019 – The BBC Symphony Orchestra will be performing some classical music by Beethoven and Schoenberg at Barbican Hall.
BBC SO playing Schumann, Brahms and Causton – 23 Jan 2019 – The BBC Symphony Orchestra will be performing some classical music by Schumann, Brahms and Causton at Barbican Hall.
BBC SO playing JS Bach’s Mass in B Minor – 2 Feb 2019 – John Butt and the BBC Symphony Orchestra and Chorus will be performing JS Bach's Mass in B Minor at Barbican Hall.
Mendelssohn, Schumann and Weber — Barbican Hall – 7 Feb 2019 – The London Symphony Orchestra will be performing some classical music by Mendelssohn, Schumann and Weber at Barbican Hall.
BBC SO playing Beethoven and Thomas Larcher – 8 Feb 2019 – The BBC Symphony Orchestra will be performing some classical music by Beethoven and Thomas Larcher at Barbican Hall.
Sir John Eilot Gardiner conducting Schumann – 10 Feb 2019 – Sir John Eilot Gardiner and the London Symphony Orchestra will be performing some classical music by Schumann at Barbican Hall.
Find more classical music in January
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