The Great Big Solo Science Experiment

Instrumentals are out! So no Eruption or Cliffs Ofdover in our experiments

Our focus is on ‘classic’ solos, so all songs here are pre-2000

We commissioned our research before the final results came in, so this list doesn’t quite match the top songs in the poll. But it’s close enough to learn from... about poking, prodding and analysing 20 of ’em under our musicological microscope in search of some common essence, a musical DNA which links them all and makes them so engaging. Is there some secret formula, a foolproof blueprint to replicate the success of these giants of rock? And if so, can our findings tell us all how to write our own ‘new classic’ solo? Read on as we find out…

How fast are these solos and how long do they last? Well, the average tempo is about 106 bpm, but this doesn’t tell us much: the songs vary considerably from the stately 58 beats per minute of Purplerain up to about three times faster in Highwaystar and Johnnyb.goode. The duration is even more variable, from the short, sweet nine bars of

Bohemianrhapsody to the ludicrous 143 bars of Freebird. In fact, over half of these solos clock in at under a minute. Long or short, it’s no barrier to writing a world-beating solo.

Our solos average about two and a half octaves of range, covering a fair bit of fretboard real estate too, although

Johnnyb.goode is an outlier, staying in one position. Layla’s slide solo is also unusual, reaching a high range beyond the fretboard.

Note: the pitch range shown here is in MIDI numbers. The guitar’s bottom E is MIDI note 40, and the top E is MIDI note 64.

Now for the matter of number of notes. Yep, we counted the lot! And we’re most interested in the average number of notes per beat (NPB), which ranges from about one NPB in Highwaystar to almost four in Floods. A better measure of shreddiness is the average notes per second (NPS). Here Crazytrain leads the pack (7.7 NPS) and the most chilled is Purplerain (just below two). However, ditch averages and measure the fastest bar and both EVH solos catch up to Rhoads, showing that Eddie’s style balances bursts with longer notes.

Rhythm’s not just for, er, rhythm guitar, so we’ve analysed our solos to see how much variation there is between the longest and shortest notes (rests count too!). If we take a solo’s longest note or rest (we’re calling this the ‘inter-onset interval’ or IOI) and compare it to the shortest one, we get a ratio telling us how varied they are. Johnnyb.goode is the least varied, but the widest by far is Comfortablynumb.