"I must say, personally, hallelujah sounds so much more beautiful than simply just 'Praise the Lord,'" Rathey said. "Hallelujah is almost music already, even without a musical setting."
That musical power comes through no matter the spelling. The Oxford English Dictionary lists eight English transliterations from the Hebrew, including alleluia, allelujah and hallelujiah. There's even an adjective: hallelujatic.
All those vowels lend themselves to music.
"It's like the perfect word to sing," Gershon said. "It has all these long vowels, and all the consonants are liquid as well. It feels like this beautiful flowing stream of sound."
Historically, the word has offered composers and vocalists the opportunity to use the voice in unusual ways, Rathey said.
"Because it's only one word and it has that final long 'ah,' it inspired composers to write very beautiful, almost instrumental lines that put celebration and the sound of music in the foreground," he said. "The focus is not on the word anymore; it's really on playing with sound and virtuosity."
Thousands of works of classical liturgical music use hallelujah, in part because there was a great need for them. In the first half of the traditional Mass in the Catholic, Anglican and Lutheran traditions, there are two biblical readings separated by several musical pieces. One of them is "Hallelujah."
"There were 'Hallelujahs' that were sung by the congregation, but at a major church it could be an opportunity for a composer to create a larger-scale piece that is performed by a choir," Rathey said.
Hallelujah was seen as so joyous that it had to be put away for the 40 days of Lent. It was considered too celebratory for such a subdued time of the ecclesiastical year.
There are stories of choir boys in the Renaissance making a tiny coffin and putting the word hallelujah in it, only to resurrect it at Easter.