Way back when I asked this, I thought it was intentional that the title screen was playing Helms Deep - Start/Loop at a slower rate, but it seems that this is tied to the audio sample rate of the file itself. Helms Deep has a sample rate of 48.000 kHz, so it is playing slower than it should be.
You can see this happening with Midna's Theme as well because it has the same sample rate.
But if you try something else with a sample rate of 44.000 kHz, like Awakening - Easy Now, you can hear the song play at a normal speed.