Counterpoint is: the use of two or more melodies at the same time in a piece of music; it was an important part of baroque music. Certain composers, such as Johann Sebastian Bach, have been especially skillful at counterpoint.

coun⋅ter⋅point /ˈkaʊntərˌpɔɪnt/ [koun-ter-point]
–noun
1. Music. the art of combining melodies.
2. Music. the texture resulting from the combining of individual melodic lines.
3. a melody composed to be combined with another melody.

coun·ter·point (koun’tər-point’)
–noun
1. Music
a. Melodic material that is added above or below an existing melody.
b. The technique of combining two or more melodic lines in such a way that they establish a harmonic relationship while retaining their linear individuality.
c. A composition or piece that incorporates or consists of contrapuntal writing.
d. A contrasting but parallel element, item, or theme.
e. Use of contrasting elements in a work of art.

When I was about 16 I read a book by Walter Piston called “Counterpoint” (like all normal 16 year old kids reading a book about music composition). Combining the melodies from two pieces of music (mixing records) can create counterpoint. I try to create a linear progression from one piece of music to the next so that the song never “ends”. The music develops and grows into something different by the use of counterpoint.