Years ago, Julian Bream did a wonderful TV series called "!Guitarra!" (the "!" at the beginning is upside down, in the Spanish style, but I can't manage that) and subtitled, "The Guitar in Spain". The series is available on a double-DVD set (on ArtHausMusik 102 003) and includes all 8 programmes in the series, lasting over 3 hours in total. The programme, in a sense, is as much about Spain, its history and culture, as it is about the history of guitars and the practice of guitar playing in Spain, but it covers all of that thrown togther as seen through the eyes of an Englishman enamoured of Spain.
In answer to Pottel's question, a lot is down to memory but I still have pocket diaries from the mid to late 1960s (except 1964, sadly) with notes (just very brief outline notes, no detail) of what I did, where I went, who I met, parties attended, pubs visited, even the odd Tv programme seen or radio programme heard. But I do not have notes on records bought (and a few sold). I also have a lot of books, to which I can refer when memory fails (and, as I get older, as memory fades). I have also kept many (not all) of the concert tickets, a few of the club membership cards, a very few handbills. In terms of Dylan, I have a fairly extensive collection of newspaper and magazine articles, some in original form, more as photocopies and avery few as typescript versions. Where I have sorted them, they are kept in chronological date order but there are many still left to sort and file. In the last decade, though, I've almost given up on collecting articles, because virtually everything comes on the internet and, printed off, they all look the same and thus very boring. There is a certain romance in handling a newspaper or magazine bought on the other side of the world and sent through the mail, to be filed in my system. There is none in the digital form, though I do admit that I have found a fair amount of long-lost and/or previously elusive material on the internet.
As time passes, I find that, more and more, I go to the sources (articles, books, discs etc) to check my memory. Usually, my memory is right (or very close) but not always. I met Cerys Matthews (of Catatonia fame and now a BBC 6 Music dj) after the last hammersmith show and suggested a track on a theme she had mentioned in a programme a few weeks earlier. To my chagrin, I attributed it to the wrong album. It was by John Stewart, incidentally.