python musical composition – the eagle is landing

Music is from my python music suite (see part trois). In this one, I wrote a simple bass sequence and beat, then mixed them with a lead sequence. The lead sequence is a looped 4 bar sequence consisting of a random 2 bar sequence to which has been appended a reversed copy of itself so that it is symmetrical.
The python music suite I wrote is just small programs to do trig and manipulate bytes in .wav files.