Least Significant Byte. If a piece of data has to be conveyed as two bytes, one byte represents high value numbers and the other low value numbers, much in the same way as tens and units function in the decimal system. The high value, or most significant part of the message is called the Most Significant Byte or MSB. Found on http://www.traditionalmusic.co.uk/music%20tech%20glossary/Music%20Tech%20Gl