I have a question about the pronunciation of the word Россия. The tips at the beginning of this section mention that the letters "o" and "a" get reduced to a schwa when a syllable containing either of them is unstressed (if you don't know what a "schwa" is, that is simply the name for the sound to which these letters reduce in their articulation). But in the audio, it strongly seems like the "o" in the first syllable is being reduced despite the fact that it's also stressed. What's going on here? Are some stressed syllables still reduced, or is the audio wrong, or is there something else going on here? In some music I've heard (Танцуй Россия by Глюкоза comes to mind), it certainly seems like the stressed syllable is on "си", but in the audio here on Duolingo, it seems pretty distinctly to be on "Рос". Any insight would be appreciated.
The audio isn't infallible. That said, I think you're also mistaking inflection/intonation for stress. Her voice rises in pitch on Рос but that isn't where the stress is - in fact, you can tell this by the way it sounds like rass not ross.
The stress in Россия is definitely not on the о but the и. You'll hear it in lots of later sentences in the course, too.
The English name is probably derived from Русь, which is older. The real name of Russia has had an O since about 16th century (originally from the Greek name), and even the name of the language became российский язык until the switch to русский язык in the 19th century.
During the reign of Ivan "the Terrible" IV (1547-1584), the name could be still be used as Rusiya OR Rosiya.