Discussion

Tempo Extraction

The average accuracy achieved by the tempo extraction method is shown in the following table:

This shows that the value extracted for tempo is successfully optimised at each step. (Outliers refer to songs that are detected with an error in excess of 1% which might skew the results unfairly).

 

Mixability Classification

The mixability classification process proved to be very succesful, demonstrated by a high cross-validation accuracy result of 87.5%.

The final accuracy of the tempo detection process for each song determined whether songs were classified as 'mixable' or 'unmixable'. A mix was assumed to be successful where the beats of two songs were found still to overlap after a period of 8 bars, or one phrase - which indicates that they do not clash. The threshold accuracy was chosen as 0.089% - a figure determined by analysis of average beat lengths in songs, and related to ensuring an overlap after 8 bars.

 

Mix Output Evaluation

The success of a mix is a subjective matter - and thus a set of 21 mixes outputted from the program was evaluated by 5 human listeners, who were asked to classify each as 'good', 'passable', or 'bad' if they heard them in a club environment or on their computer at home. This yielded the following results:

	Good	Passable	Bad
Person 1	11	4	6
Person 2	9	7	5
Person 3	8	6	7
Person 4 (DJ)	8	5	8
Person 5 (DJ)	8	7	6
Average	41.9	27.6	30.5

Analysis of the mixes created found that most unsuccessful mixes were created because of a poor song alignment rather than an inaccuracy in tempo detection.