Choose the instrument on which you would like to play the tarantella. Many tarantellas are played on the guitar, which is an ideal accompanying instrument for dancers.
Pick the version or piece you would like to learn. There are many pieces with "tarantella" in the title, including the traditional tune, "Rabbia e Tarantella" from Ennio Morricone's score for "Inglorious Basterds" and advance classical guitar pieces like Mario Castelnuovo-Tedesco's "Tarantella."
Sight-read through the music, meaning you play through the entire song without ever having seen it before. Sight-reading is an ideal step so you can identify what places in the music are difficult for you, and you can figure out where you need to place your fingers and which fingers to use. For example, the Castelnuovo-Tedesco piece is very advanced and long, and you will want to read through it to listen to how it sounds; this piece is not for beginner players and requires some knowledge of classical guitar techniques.
Highlight or circle any difficult parts after you read through the piece. Practice the song one phrase at a time, and focus on any spots that are particularly hard to play.
Play through the piece slowly. Gradually speed up the tempo as you become more proficient. To play the traditional "Tarantella," barre your index finger of your fretting hand across the first and second strings on the seventh fret. Play the first string twice, the second string twice, the first string twice again and the second string once by picking with your strumming hand; you can use a pick or your fingers. On the second string, play the seventh fret twice, eighth fret three times, tenth fret once, eighth fret once and seventh fret once. For the next phrase, on the second string play the seventh fret twice, the fifth fret twice, the seventh fret once, the fifth fret once, the third fret twice, the fifth fret once, the third fret once, the second fret twice, the third fret once, the second fret once and the open string once. Follow along with a piece of music or the guitar tablature. Play along with a recording if desired.