I was re-reading this chapter and wanted to bring up a thing or two about Brandon's first appearance in the novel. For instance, there's his friendship with Sir John:

Colonel Brandon, the friend of Sir John, seemed no more adapted by resemblance of manner to be his friend, than Lady Middleton was to be his wife, or Mrs. Jennings to be Lady Middleton's mother.

It got me thinking of C.S. Lewis' commentary on types of love and how affection can exist where there is little to no similarity of taste or temperament. Brandon is described as "silent and grave," which is certainly NOT the kind of person I'd imagine as being a good friend of a man like Sir John. But maybe it's better that way---Sir John and Mrs. Jennings are both so full of energy they pretty much suck all the air out of the room! 8-)

More on Brandon:

. . . but though his face was not handsome his countenance was sensible, and his address was particularly gentlemanlike.

I hadn't thought of it before, but with the title of this novel being Sense and Sensibility, the description of Brandon cuts both ways. Is he "sensible" as we would call it now (i.e. practical and levelheaded and intelligent) or "sensible" in the more romantic definition like Marianne? A man of strong feelings? Or both? And I can't help thinking of Elizabeth Bennet's "more gentlemanlike manner" with that last part of the phrase. If Brandon is "particularly gentlemanlike" it seems to be a mark in his favour from the narrator.

And finally, Marianne's reaction to him after she plays the piano:

Colonel Brandon alone, of all the party, heard her without being in raptures. He paid her only the compliment of attention; and she felt a respect for him on the occasion, which the others had reasonably forfeited by their shameless want of taste.

Yes, Marianne behaves at times as if she's clueless, but every time I'm irritated with her this passage raises my estimation fo her just a bit. She seems to recognize that Brandon's response is worth having---the subtle "compliment of attention." And I think it's important that she feels some respect for him, though of course the chapter ends with more humour at her expense:

She was perfectly disposed to make every allowance for the colonel's advanced state of life which humanity required.

I just think JA is especially brilliant in these passages with how much she reveals in how few sentences.