Place this clip early in a horror sequence as the background bed, then layer a door knocking sound effect before the reveal and finish with a dramatic dun dun dun sound effect once the threat is fully visible on screen.
About this sound
This clip is a slowed, creepy rendition of Tiptoe Through the Tulips lasting about thirteen seconds, sung in a high falsetto over sparse ukulele. It feels eerie and uneasy, because the innocent melody sounds fragile and slightly wrong. The song dates to 1929 and was popularised by Tiny Tim in 1968, later appearing in Insidious.