I was up at Westminster Cathedral on Saturday, and had a quick look at the music listings for this week,
http://www.westminstercathedralchoir.com/cmsAdmin/uploads/ml151011.pdf

Monday 12 October
17:00 First Vespers of S Edward the Confessor (Men's voices)
Magnificat primi toni - Reid (15)

17:30 Vigil Mass of S Edward the Confessor (full choir)
Missa O quam gloriosum (k, G, a) - Victoria
O Quam gloriosum-Victoria
Jesu dulcis memoria-Dering
Credo said,
sanctus Viii

Tuesday 13 October Feast of St. Edward the Confessor (1st Class)
17:00 Solemn second Vespers (Men's voices)
Magnificat septimi toni - Ogilvy (74)

17:30 Solemn Mass (full choir)
Mass for four voices (k, G, s, a) - Byrd
Justus ut palma-Mawby
Ave Verum corpus-Mawby
Credo IV
Organ: Pæan (six Pieces for organ) - Howells

The Anglicans just up the road, in the Abbey St. Edward founded, will also be singing Evensong on Monday night etc. Flick through to find the other music this week,
http://www.westminster-abbey.org/music/choral-services?SQ_CALENDAR_VIEW=day&SQ_CALENDAR_DATE=2015-10-12

The choirs of both Westminster Cathedral and Westminster abbey will be singing the following at the abbey on Friday,
http://www.westminster-abbey.org/music/choral-services?SQ_CALENDAR_VIEW=day&SQ_CALENDAR_DATE=2015-10-16