The collection contains acoustic intensity data of 50 pieces of commercially available music (3 large-scale compositions, 2 computer-interactive improvisations, and 45 short electro-acoustic works). Roger wrote scripts in Praat ( a free software programme for acoustic analysis) to analyse intensity durations and intensity change rates of successive rises and falls in the pieces. Intensity is measured window by window using the 'energy averaging' option within Praat, and using a pitch range for the analysis from 20Hz upwards, which provides intensity as Sound Pressure Level (SPL) in dB. Each file contains two columns of data, the first, 'sliceedntime(sec)' indicates the time at which the measured intensity slice ends. The first slice is either 0.16 or 0.17 secs (for reasons related to the analysis technique), while all subsequent slices are 0.04secs long (40msec). The pieces vary in length. The second column 'intens(dB)' indicates the measured (unweighted) Sound Pressure Level in dB. The files are zipped, so unzipping software is required to access the data.