Forgive me for even opening a discussion, but since we are in a forum and I remain convinced that forums should contribute to improving the knowledge of those who frequent them, it might be worth it.
I continue to read (not only here, but it's the same elsewhere) accellerare, accellerando, accellerazione etc.
Well: it is wrong!
The verb accelerare is written with a single "l", because it derives from celere!!!
This is one of the most common errors in the Italian language. Others are, for example, qual è (which should be written without an apostrophe, so NOT qual'è), meteorologia (and NOT meteREOlogia, because it derives from "meteora"), fa [third person singular of the verb fare], which should be written without an accent (mi fa male, therefore, NOT mi fà male), whereas dà [third person singular of the verb dare] is written with the accent to distinguish it from the preposition (Mi dà ai nervi! but Da che pulpito! and - attention! - Da' qua, come Fa' un po' vedere, Sta' attento which must be written with an apostrophe - NOT with an accent! - because they are elisions of "Dai", "Fai", "poco", "Stai").
I apologize again; it is true that the forum deals with musical topics, but since the decline of our Italian language is often stigmatized precisely because of internet language and, above all, SMS, misled by convenience and to save precious characters (un pò better occupies less space than un po' meglio, but it is wrong...), I believe we should worry a little more about how we write.