History is built into the very walls of Town Hall, Birmingham, and when City Organist Thomas Trotter plays the organ there, that heritage springs vibrantly to life. The first of this season’s lunchtime concerts features two composers who actually performed in Town Hall themselves: Mendelssohn and Stanford. But they’re just part of a musical journey that spans five centuries in one hour, from Susato’s lively medieval dances to Dan Locklair’s 20th century classic.