calliope

For our next show the choir I sing in is rehearsing a number of new songs for which we have commissioned bespoke arrangements. One of them is Jacques Brel’s Carousel, aka La Valse à Mille Temps, with English words by Eric Blau.

Carnivals and cotton candy,
carousels and calliopes.
Fortune tellers in glass cases,
We will always remember these.

To be honest, these lyrics are somewhat opaque to British ears. In BrE we would speak of funfairs rather than carnivals, candy floss rather than cotton candy, roundabouts rather than carousels, and steam organs rather than calliopes.
Because we’re not familiar with the word calliope, we also don’t know how to pronounce it. The chorus’s assistant musical director has made rehearsal tracks of the music for us (tenor 1, tenor 2, baritone, bass) — an excellent thing to do, and very time-consuming for him, but something which makes all the difference for those of us trying to learn our parts despite shaky sight-reading skills. He pronounces kæliˈəʊpeɪz.
So I have written to the musical director

I have been researching the word “calliope”, which features in our new chorus item Carousel.
All the dictionaries I can lay my hands on (including my own Longman Pronunciation Dictionary) give the pronunciation as having the stress on the second syllable, -li-, which is like “lie”. The final syllable is like “pea”. In the International Phonetic Alphabet, it is represented as kəˈlaɪəpiː (see the attached scan from the big Oxford English Dictionary). The vowel sounds and the stress placement are comparable to those of the word “variety”.
In the lyrics of the song, it is clear that the “-pes” syllable is meant to rhyme with the word “these” at the end of the next line. So if we pronounce it “pays” we are missing that intended rhyme.
Obviously, your decision is final for the chorus: we will pronounce the word in whatever way you lay down. But I thought you might like to know these findings.

Calliope was, yes, one of the nine Muses, in fact the chief of the Muses, daughter of Zeus and Mnemosyne, mother of Orpheus, and inspirer of Homer. In Greek her name was Καλλιόπη (‘beautiful-voiced’). The -op- part has nothing to do with vision: it represents the noun ὄψ ops ‘voice’, cognate with the ep- of epic.

Like other Greek names, this one too passed through Latin on its way to English, thereby becoming subject to the Latin stress rule. Latin stress is sensitive to the weight of the penultimate syllable: since the o is short, stress falls on the preceding i. Being prevocalic, this i has to become long in English. The GVS turns it into the modern diphthong aɪ. Coming upon calliope, Calliope as a written word for the first time, you can’t predict its pronunciation without knowing the classical quantity of the o.

There seems to have also been a vulgar AmE pronunciation ˈkælioʊp (perhaps it still exists) — but that wouldn’t fit the music, which requires a four-syllable word.