Rule reminder
Italian uses suffixes to modify the size, degree, or attitude towards something without using a separate adjective. Diminutives (-ino, -etto, -ello) = small or endearing. Augmentatives (-one, -ona) = large or emphatic. Pejoratives (-accio, -uccia, -astro) = negative or contemptuous. These suffixes change meaning significantly and are very frequent in spoken Italian.
What does 'libretto' mean compared to 'libro'?