What Shakespeare's play had music composed by Felix Mendelssohn, featuring one of the most frequently used wedding marches, generally being played on a church pipe organ?
Wedding March (Mendelssohn):  It is one of the most frequently used wedding marches, generally being played on a church pipe organ. A Midsummer Night's Dream (Mendelssohn): At two separate times, Felix Mendelssohn composed music for William Shakespeare's play, "A Midsummer Night's Dream".
A Midsummer Night's Dream