Do you know any music band whose songs are mostly in latin? Or do you know any english poems with some latin sentences intertwined? Or maybe some artificial languages based on latin from some s-f / fantasy books?
There may be a music band, but I don’t know of any. Other members might.
Poetry with Latin and English intertwined together is called macaronic poetry in English. Wikipedia has a discussion of ‘macaronic language’ (in English) here:
Macaronic language - Wikipedia.
There is one example of a macaronic poem called “The Motor Bus,” which dates from 1914. This is the link:
Hope this helps.
Thank you! 
Content edited
For example Enigma, Era, Gregorian,
In a couple of things Apocalyptic, Within Temptation…
I think you can find a lot of bands that sing in Latin … It is pleasant to listen to rock with vocals in Latin, something special, as if imposing it.
(Myślę że można znaleźć wiele zespołów, które śpiewają po łacinie … Fajne słuchać rokmuzyka z wokalem w języku łacińskim, Jest coś majestatycznego w tym.)
There is of course a lot of classical religious music in Latin. A singer named Enya put out some records with Latin lyrics, probably a dozen years ago. And then, of course, there’s always this, which used to be available online to listen to (and still may be findable): http://www.amazon.com/Legend-Lives-Forever-Latin-Ammondt/dp/B000000S0O .
In animated cinema: Disney’s;The Hunchback of Notre Dame did use a good deal of Latin in the film.
An anonymous poem from the 14th Century that mixes English and Latin appears in The Oxford Book of English Verse: 1250-1900, edited by Arthur Quiller-Couch. Titled “A Hymn to the Virgin,” the 27-line poem is online here:
Project Gutenberg makes the entire book available under the title “Bulchevy’s Book of English Verse by Sir Arthur Thomas Quiller-Couch”:
“A Hymn to the Virgin” occurs as poem number 6.
The science fiction novel from the late 1950s, A Canticle for Leibowitz by Walter M. Miller, Jr., has a lot of Latin in it. Here’s a webpage, listing and briefly discussing most if not all of the Latin in the book: http://en.wikipedia.org/wiki/List_of_Latin_phrases_in_A_Canticle_for_Leibowitz .
The first time I read this book, in my teens, I knew no Latin but thought the book was great, anyway. And it is–a very good story, with a serious message, and beautifully written. I recommend it very highly. Knowing Latin makes it even better.