...videos offer a personal dimension, a social element to the sharing of music and musical experiences, even if some of them are not much more than four minutes of gurning at the camera. /end

...derive at least part of their content from taking recommendations from their viewers, which can lead to videos which are a tough but compelling watch due to the challenging nature of the material that audiences have recommended, e.g. Korn's 1994 track 'Daddy'.

If nothing else, reaction... /5

...great performances for the first time or responding to the unexpected (look for reactions to Living Colour's 'Cult of Personality' or House of Pain's 'Jump Around' and you'll see what I mean.

And let's not forget that reactions can be deliberately induced by their audience. Many 'reactors'... /4

...social apes (and non-apes as well) comes with the evolutionary territory.

We derive pleasure and, I think, a sense of validation and belinging from seeing other people react positively to music that we ourselves enjoy. People get a buzz out of watching others discover great music and... /3

...with analysis and informed commentary based on their particular skill set.

Even without that added value content, reaction videos can offer a visceral experience that many people find compelling. We are, after all, social apes, so an endless fascination with the social behaviour of other... /2

It doesn't have to be be truncated and simplified - many of the best reaction videos are produced by professional musicians, technicians, producers, tutors, vocal coaches and even composers, so you get their reaction and opinion (often to music that's outside their normal wheelhouse) together... /1

Now I do use bookmarks quite a bit, mostly when I'm using my phone and someone's tweeted a link to a research paper I want to download to my laptop.

Sadly, no - when I was blogging regularly about abortion 12-15 year ago, it was nigh on impossible for women to obtain an abortion in Scotland any later than 16-18 weeks.

Clearly nothing has changed over time.

Zen and the Art of the Ham and Cheese Sandwich.

It's a fair question, not least because Googling 'Ask for Angela' alongside keywords such as 'evidence', 'statistics' and even 'case studies' turns up absolutely nothing to show the scheme is the least bit effective.

Not sure the Hydrocephalus Association will be overly impressed with the ad agency who dreamt that up.