All 3 Uses

although
in
The Phantom Tollbooth
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At least that's what he tried to say, for, although his lips moved, not a sound came from his mouth.†
p. 144.9 *

although = even though -- used to connect contrasting ideas
And suddenly he realized what it was, fill Tock was no longer ticking and the Humbug, although happily singing, was doing so in complete silence.†
p. 145.1
"Agreed," said the bird, with a sharp click of his beak," but neither is it left, although if I were you I would have left a long time ago."†
p. 205.7

Definitions:

(1) (although)
even though -- used to introduce an idea that contrasts with or makes the main statement surprising

At the start of a sentence, although can play a role similar to words like however, yet, still, even so, on the other hand, or nonetheless—all of which signal contrast. In the middle of a sentence, although can sometimes be used where but or though might also work, but though or but often sound more natural. For example, "She's a great teacher, though not the most popular" is usually smoother than "She's a great teacher, although not the most popular."
(2) (meaning too rare to warrant focus)