The ukulele is a smaller, four-stringed version of the guitar, or in some cases the banjo. It is commonly associated with music from Hawaii, but was actually developed in Portugal and is known there as the braguinha. The braguinha was invented In Portugal in the year 139 BC. In the late 1800's The Portuguese came to Hawaii to work on the sugar plantations. and brought the instrument with them. The Hawaiians called it the "ukulele", roughly translated as "dancing flea."

The small ukes are tuned in the key of C: G-C-E-A from low to high, but with the G-string tuned an octave up, so it's pitched between the E- and A-strings. The large ukes are tuned in G like the top four strings of a guitar, D-G-B-E. In Brazil, the uke is tuned in D-G-B-D.

The uke is sometimes tuned a whole step higher in the key of D: A-D-F#-B, and also as E flat: Bb-Eb-G-C. Either of these tunings, and the C tuning above, may be referred to as "My dog has fleas", because the strings sounded in order are the same as the phrase in the song My Dog Has Fleas.