every beat is a quarter note. Two digits (…:34:…) makes each an eighth note; have four digits (…:3456:…) and each is a sixteenth. Three digits (…:345:…) are possible, the first one being a quarter and both others each an eighth, but might be confusing. Some musicians put a comma or dot inside the beat (…:3,45:…) to remind the singers of the unequal duration. But the real use is with a tie (…:3-4:…), to have a dotted quarter note followed by an eighth. and signatures are rarer, but work the same as the quarter-based signatures except that all beats are twice as long. One digit in a beat being a half note and so forth. Occasionally one finds (like |3:4|) and (like |3:4:5:6|) time signatures. Then every single digit is a dotted quarter note, while the most common occurrence is 3 digits in one beat, (…:345:…) each of them of course one eighth. Also here two digits are possible, the first one being a quarter and the second an eight, but again with all the pitfalls as the 3 digits in the quarter-note notation. It is mainly used for (…:3:-4:…) meaning a note worth five eighths (dotted quarter tied to quarter) followed by a single eighth. References http://www.tau.olunga.to/fasi.html Hebert, D. G. (2008). Music Transmission in an Auckland Tongan Community Youth Band, International Journal of Community Music, 2(1). Tongan music Musical notation