I was browsing through some of my music CDs, and I found a piece titled "Fiorellin di Siepe" by Raffaele Calace, but in this collection site, it's listed as Fiorellini di Siepe. However, if you open the pdf link to the sheet music, it's once again titled "Fiorellin".
As far as I understand, "Fiorellini di Siepe" means "Little Hedge Flowers," right? Does "Fiorellin" mean anything, or is it a typo?
It is very common poetic (and musical) usage to drop the last vowel of a word to change the number of syllables of a verse: Maz-zo-li-no becomes maz-zo-lin (quel mazzolin di fiori):
Amor<e>, ch<e> a nullo amato amar<e> perdona,
mi prese del costui piacer<e> sì forte,
che, come vedi, ancor<a> non m<i> abbandona.
Since the last vowel almost always determines gender and number of something, the elided form is ambiguous and usually considered singular when seen alone, but it depends on the word.
So, Fiorellin might mean either little flower or little flowers.
Putting together an answer from Hachi and DaG's comments:
This is a case of poetic "elision". While elision is more common in singular forms, in poetry, it's not unheard of to use elision on a plural form, especially in poetry and song, as in this case.
