Fearful Harmony is the name given to the startup error on the PlayStation 1 whenever the user inserts a non-PSX game (e.g an Ubuntu CD or any pirated game).
On startup, the Sony Logo will appear as normal, and then on most cases, it will attempt to boot up the improper disc in the PS1, however, it will play the second sound without the PlayStation logo. This sound is different to the normal PS1 bootup sound. The word 'Sony' will still be on the screen, and the orange-yellow diamond will still be there too.
This error screen varies, depending on what disc you've inserted and what PS1 model you have. Some show the diamond, the acronym SCEA and the word PlayStation will be appearing and disappearing.