People tend to check in during these times:
The RNCM, formed in 1973 from the merger of the Royal Manchester College of Music with the Northern School of Music, has, for many years, been the first choice institution for a large number of aspiring professional musicians from the UK and overseas.
The lunchtime concert are great (about 30-40 mins) - and they're free!
Have a look at the live music sheduled for some of Manchesters best hidden shows. A great collection of live venues (concert hall and large theatre) catering for classical and contemporary tastes.