Monster Behind the Door by Catherine Wilson is mysterious, intriguing with a quirky feel.  
 
The use of semitones / half-steps helps create an eerie quality that is reinforced by the use of tritones in the riff-like left hand.  The final major chord makes us wonder whether there was ever actually a monster behind the door!
 
Instrument: Piano Solo
 
Approximate difficulty level: Grade 2 - 3 / Early Intermediate
 
Key: Tonal centre of C, uses the notes C, D, Eb, F#, G over different octaves
 
Time signature: 4/4
 
Features: Intervals of semitones / half-steps, minor 3rds and tritones, left hand ostinato-style riff, hand crossing
 
Focus: To explore unusual tonality, build confidence lifting hands away from the keys, maintain a regular pulse