Sol in Italian is the musical tone G in English.
"Joking" in English is scherzando, which also is used in musical notation for playing pieces playfully, in Italian.
Il convitto musicale in Italian means "the musical boarding school" in English.
"Always" is an English equivalent of the Italian word sempre. The translation may be applied to musical and non-musical contexts. The pronunciation always will be "SEM-prey" in Italian.
Sweet in musical terms would be Dolce (translating in italian directly to sweetly, and sometimes referring to desserts)
(Il) dramma musicale is an Italian equivalent of the English phrase "musical drama." The pronunciation of the phrase -- which literally translates as "the musical drama" -- will be "eel DRAM-ma MOO-zee-KA-ley" in Italian.
(La) direzione musicale is an Italian equivalent of the English phrase "musical direction." The pronunciation of the phrase -- which literally translates as "the musical direction" -- will be "la DEE-rey-TSYO-ney MOO-zee-KA-ley" in Italian.
"Play quietly!" in English is Giocare in silenzio! for having fun and Toccare in silenzio! for playing musical instruments in Italian.
Prestissimo is an Italian equivalent of the English musical direction "as fast as possible." The pronunciation of the masculine singular superlative -- which literally translates as "fastest" -- will be "prey-STEES-see-mo" in Italian.
"Gentle" is an English equivalent of the Italian musical term dolce. The pronunciation of the feminine/masculine singular adjective will be "DOL-tchey" in Italian.
"Extremely fast, very lively" is an English equivalent of the Italian phrase presto, molto allegro. The masculine singular singular, adverb, and masculine singular adjective reference musical terminology which asks of the performer brisk speed. The pronunciation will be "PREH-sto MOL-to al-LEY-gro" in Italian.
The letters mf on an Italian violin refer to mezzo forte, an Italian musical term for "medium loud."