Thanks to Ewan McIntosh for pointing me in the direction of this post by Donald Clark. Citing 1976 research by A. H Johnstone and F. Percival into attention span in 90 Chemistry lectures, with 12 different lecturers, it describes the highs and lows of attention in a 60-minute lecture.

• 2-3 minutes to settle down
• 10-18 minutes of attention
• progressively shorter attention periods, dropping to 3-4 minutes towards end

These conclusions were not formed by an impression of attention but by the subjects’ ability to recall content.

The reason this grabbed my attention is that, following a long period of evolution, all my lessons across a 5-school orbit, last 30 minutes. Allowing time for pupils to travel from the previous class, unpack and then reverse these features in order to return punctually, the hands on instrument time must be around 22 minutes. For many pupils, this feels about the right time.

All Guitar Group rehearsals, except those of the East Lothian Guitar Ensemble*, last 30 minutes. If pupils arrive on time, set up quickly, engage and play well it’s not unknown for them to be released in 15-20 minutes – particularly as the concert approaches and the spectre of staleness taps at the window (where the luxury of a window exists).

Yet, curiously, the reason we migrated from 35- or 40-minute lessons to 30 minutes, is that general school timetabling has gone in the opposite direction – all periods in the secondary schools I visit are now 60 minutes long. Apart from this simply being too long for an instrumental lesson and too long for pupils to be out of class, this would permit only six instrumental lessons per day and so it seemed natural to opt for 12 x 30-minute lessons-per-day – so natural in fact that I can’t recall discussion seeming necessary in any school.

Does this mean that we have been blessed with the ideal length by virtue of our colleagues veering blindly in the wrong direction? Well, only if it was still 1976 and if school teaching resembled the kind of university lecture where one person was active while the others listened in reverential silence, their most dynamic input being the taking of notes**.

Donald Clark writes interestingly about Tyrannies of Time one of which rings a bell with me – the dip in performance which some pupils seem to experience when their lesson immediately follows lunch. In such cases, I ask the pupils if they’d mind my asking what they had for lunch, and my fears that a matrix of E-numbers has brought about the cognitive dip are usually groundless.

* Contrastingly, and for purely practical reasons the six annual East Lothian Guitar Ensemble rehearsals take place from 1:30 – 3:30 – minus time for pupils, transported from distant schools to walk from the drop-off point to the venue – minus tidying up time – minus a break in the middle – well it is a Friday afternoon, after all.

** During my five years at music college, my note-taking habits changed from the frenzied assembly of a wretched, illegible and barely revisited scrawl, to simply listening, empty-handed. In the end, I could no longer see the point in inaccurately recreating what already existed in the library, at the cost of my ability to concentrate and enjoy the lecture.