I am reading the book "Gödel, Escher, Bach", in which the author tries to present concepts in mathematics, drawings and music as instances of a certain "pattern", that he calls "strange loops". He makes several comments about Bach's music, in particular, as the title suggests. So, he talks about the fugues, sonatas and partitas, modulation, themes played against themselves, how Bach manages to get two or more musical lines going simultaneously and so on.

But I don't understand a thing about these musical concepts. I have tried to listen on YouTube to some of the compositions he mentions in the book, but my stupid brain only hears a stream of notes flowing. I can't recognize the patterns he talks about, nor can I grasp, for example, the fact the the "Canon per Tonos" rises successively until it reaches the key C again. 

So how can I learn more about these musical concepts, so as to better follow the book's main ideas? To make this question narrower, I'm not asking for general references to learn about music, but something very specific to the content of the book, so that I don't miss important information (and fun) from his exposition.


Question: How can I save messages from a particular sender in a particular folder in Gmail?
Answer: A strength of Gmail is the use of labels, instead of folders.  You need to create a filter to automatically add a label to the message and automaticlly archive the messages.

To create a filer for a message that frequently is sent to you:


select or open a message you want to filter
Under the More pulldown select the command: Filter messages like these
You will then see the form open up with the FROM box filled in.
Google with then show you the messages that the filter has found.
Click create filter with this search. 
You can now specify if you want to:

Skip the Inbox (Archive it)
Apply the label:
Also apply filter to x matching conversations.

Click create the filter.


Archiving the messages keeps the message, it just removes the inbox label from the message. Labels can be used to search using label:mylabel. Labels are listed on the sidebar menu so that you can quickly jump to a filter that just shows the messages with that label. Plus messages can have multiple labels. 

You can edit/delete/create filters under Settings(gear)->Filter