Dennis Fowler posted a comment on a classical meetup event about the similarity of the opening theme of Mahler's Symphony Number 3 to the main theme of the fourth movement of Brahms's first symphony. Was it a case of Mahler paying veiled tribute to Brahms? The Mahler theme, he said, sounds like a “minor-key ghost image” of the Brahms.
I had never noticed the similarity, so his comment inspired me to fire up MuseScore to make a direct comparison of the two themes. Here is the result.
It's easy to compare the themes as they are both notated in the key of C major although the Mahler is actually in F because of the way horn music is annotated. You can decided for yourself if this was Mahler's homage to Brahms, but I think the similarity is too great to be accidental.
Here is the fourth movement of the Brahms symphony
Mahler's Third Symphony