The Sacred Congregation for Divine Worship and the Discipline of the Sacraments has something to say on the use of Churches for concerts.
adoremus.org/concerts.html
Basically a church is the house of God and his place of worship. It is acceptable to use the Church for a musical performance that is in keeping with an act of worship. In those circumstances the Blessed Sacrament should remain in place. If the performance is not one suitable to take place in front of the Blessed Sacrament, it is not suitable for a Church.
The exception is where there is a building used as a hall, but where Mass and the Sacraments also take place. When such a building is not in use as a place of worship, the Blessed Sacrament should be reserved in a place away from the main hall. Usually, this type of building includes a small chapel available for devotions and weekday Masses and the hall is only used for Mass on Sundays and Holidays.