(zajac) the use of the figured bass adding symbols above these bass notes is really the whole foundationr modern concept of harmony. [classical piano music plays] (narrator) the harmony that underlies much of the standard classical and popular music we hear today was developed by the 18th century. it involves rules and conventions about how chords are constructed and how they progress from one to the next. (woman) a chord will have certain sounds or colors that give the composer a lot of choices in how he's going to make a piece sound. in fact, it's kind of like a painter's palette. they have a palette of different colors to choose from, and a composer has different chords or harmony to choose from to make his piece come alive. when a composer takes chords and strings them alo one after another, that's called a chord progression. here's a very simple chord progression. [plays chord progression] three chords coming back to the first chord. in a chord progression, often the chords will lead to a point of tension, and then you have to have resolution. see if you can hear the tension of this