High-Pitched Male Singing Technique
Puzzle 1 of Day of the Dead Hard Pack
Question is: High-Pitched Male Singing Technique
and the answer is: FALSETTO
Word Meaning:
FALSETTO — (singing, uncountable) The "false" (singing) voice in any human, usually airy and lacking a purity of vowels; created by using the next highest vocal folds above those used for speech and normal range singing. It is commonly confused with the head voice register.
Definitions from Wiktionary.