How long, how long must we sing this song?

In my academic research I’ve been investigating the ‘constraints of song’ – that is, what defines a song, and what creative decisions are likely to make it more (or less) successful. The simplest of these is track duration, not least because it’s easily measurable.

I couldn’t find any statistical study of track length over time, so did a quick analysis myself, finding the top 10 best-selling singles of each decade 1960s-2000s (from everyhit.com) and comparing them to the track runtime from the relevant iTunes download. The full spreadsheet of my data can be found here (rough paste below).

Findings:

• The mean average length of track rose from 2:43 in the 1960s to 4:03 in the 1970s but then (from the 1970s) fluctuated by no more than 0:18 per decade, maintaining an average length of around 4:00 over 40 years.
• The median song length, from the 1970s, is even more conservative, with only 0:12 change (3:47 to 3:59) between the 1970s and 2000s.

Conclusions

• Best-selling hit songs were shorter in duration during the 1960s (although this may have been dramatically affected by some very short early Beatles’ singles, five of these appearing in the decade’s top 10, all with a duration of less than 2:30).
• The mean average duration of best-selling hit songs has not varied significantly by decade since the 1970s.