Is it possible playing C mixolydian notes in a song in the key of C?

Yes. In principle you can (and should) do anything you can think of, and evaluate if you want to do it based on how it sounds. If it sounds good to you, go for it. That said, using modes of a key is very common.

1. What key is C mixolydian in?
2. What are the notes of a mixolydian scale in the key of C?
3. Is G mixolydian the same as C major?

What key is C mixolydian in?

The same notes can be found in different Major and Mixolydian scales: C Mixolydian – F Major. C# Mixolydian – F# Major. D Mixolydian – G Major.

What are the notes of a mixolydian scale in the key of C?

The mixolydian scale starts on the 5th note of the major scale and ends on the fifth note. For instance, the C major scale is C, D, E, F, G, A, B, and C. The fifth note of C major is G. Therefore the 5th mode of C major is G mixolydian: G, A, B, C, D, E, F, and G.

Is G mixolydian the same as C major?

Yes, the Mixolydian mode is exactly the same as the major scale - it just begins on the fifth note. For example, C major (C D E F G A B) gives you G Mixolydian (G A B C D E F). And, though the notes are identical, reordering them means the gap (aka interval) between the root and the seventh note is different.