Thank you for the guidance; please bear with me as I am really starting to struggle with the language style and content of the windows in MB (but I recognise that I am achieving considrably more that I have been able to using iTunes).. I know I am old (my first introduction to symbolic programming languages was in 1959, when things were rather primitive) but I don't think I'm significantly intellectually impaired or lacking in commitment.
I seem to have stumbled for a while trying to parse your instruction 'drop the menu File' - I could not find a menu File (File of menus ?) or a file called 'menu' on my system (which contains about 3 million files) until I finally ealised that I was misunderstanding the verb 'drop' and that what you were instructing me to do was to invoke the action to add a file or files to my library through use of the top level menu named 'File'. That is what I had been doing.
On the particular audio file with which I am having a problem, this action results in a message in what I assume is a status information area at the bottom of the window. The message reads 'No files added' - which I am painfully aware of. What I should like to know is 'why ?'. So far I have found just the one audio file that behaves in this way, but I see there are a number of other files in my windows structure which I have not yet attenpted to add into the library, so at this point it is not possible to say if there any common factors in these 'not added' files. But I can say that the one problem file I have identified appears to be no different to many other files which MB has added to the library.
I am unable to " Go to Preferences/Layout (1)/left sidebar" as there is no menu or sub-menu labeled 'Preferences' in my installation/configuration of MB, which I have not changed in any conscious way from the default created by the installation process.
But I do see that I now have an icon towards the top right of the MB window that looks like a letter or printed object; hovering over this icon with my mouse pointer tells me this is my inbox (of which more later)
I do have a black rectangle (but not a blue square) which, on mouse hover, appears to be the 'Configure Layout' button. I have been able to show the left side bar panel. Doing this causes the Inbox icon to disappear. It is not clear to me what the purpose of the side bar panel is in terms of the problem I am having, aside from proving to myself that the problem file does exist within my Windows file organisation.
I am unable to sensibly parse your advice " Check the wiki psychoadept linked you to for discussion on what the Inbox is for and if you care to use it". The sentence appears to be telling me that some 'agent' named 'wiki pyschoadept' or 'psychoadept' has linked me to some object, but I have no undersanding of what or where this agent is or how it has linked me to some information. I don't believe MB has asked me for an email address. As a matter of basic computer security I deny all requests to link to my computer systems, both at the firewall and at my router.
The contents of the inbox - when I could see it - has totally mystified me. This has to be the subject of another forum post , as it is off topic here. Suffice it to say that the inbox has identified a number of duplicate files which it has therefore hidden but the inbox window utterly fails to tell me what they are duplicates of, i.e. what characteristics in the file properties are duplicated - time & date? File size ? File Name ? File content ? Encoding method ? Artist ? Album Artist? Year of composition? Composer? - and so on. So I am unable to determine what would have to be changed to eliminate the duplication. Te duplicate files listed are othrorgonal to the file which I cannot persuade MB to add to the library.