Vandemataram song. Set to the raga Desh.
The arohana or ascend has the N3 swara. When C is the Sa, the B note.
In the avarohana, N2 swara, the Bb note is used.
Some parts of the song have phrases with G and B note in it, often leading to the higher C note, the Sa.
Other parts of the raga or song can have phrases like p n2 d2 p (notes: G Bb A G). The presence of the G and the Bb notes gives us the chord option of G minor.
There are other ragas and songs, where the G3 and G2 are used. Sahana or Madhyamavathi for example. Kadhal rojave or thumbi vaa for example – which I have played using the D and Dm chords.
Assume one of the notes as the main scale and consider the other as extra. For example, in the case of Vandemataram, consider it as a scale with the B note, while Bb rule is observed in the descend. Of course, with time, you can have a better feel for the raga and scale and accept it as a whole with all its differences!
Beauty and freedom enters through those changes we allow.