Too Specific Exorcism No Good

An exorcism is always pronounced at the beginning of the lunch hour concerts:

Ladies and gentlemen may I ask you all to please turn off your mobile phones.

It works, for mobile phones, but it's far too specific, if you ask me. Take today for instance. Marija Bajalica was playing Haydn's Piano Sonata No 38 in F on the piano. How hard would it have been to have added this exorcism before she began:

In the name of the father the son and the holy ghost don't hum please, amen.

Because we were plagued during the entire first movement by a hummer.

And another even stranger spirit had entered the hall untroubled by an exorcism. I saw evidence of this spirit as Marija played Schumann's Etudes Symphoniques. These are a series of variations each more moody than the last, except for the last.

I was watching the hands of Marija, which were long and catlike. I was sad because I couldn't see the tips of her fingers, due to the angle at which I was sitting.

I looked idly down at the floor under the seat of the man in front of me. I saw a square of light, illuminating stiletto marks in the wood, and 2 faint lines where the floorboards joined. Suddenly there appeared in the lower half of the square of light, as though performing on a tiny stage, the shadows of the tips of 3 fingers dancing rhythmically to Marija's etude.

What could they have been but the spirits of Marija's hidden fingers, and how easily could their escape have been prevented?

In the name of the father son and holy ghost keep your hands to yourselves amen.