What Is the key of the song and scale used?

[ssyniu]

Hi
Would you be able to help me to establish if this song is a blues song in the key of G:


https://www.youtube.com/watch?v=4JlEcsY-tjY


I am not very good in understanding blues, but blues uses different scales than classical music.
Is this song sound is G blues scale (G,Bb,C,Db,D,F,G)

I did replayed intro and main groove bass line:

Main Groove bass line

https://soundcloud.com/ssyniuy/bass-main-groove

Notes played G,F,D,G,C,C,G,F,D,G.

Intro bass line

https://soundcloud.com/ssyniuy/bass-intro

It sounds like he is playing G,G,A,Bb,Bb,B,C,Db,D,Eb. for the first 4 bars.

Thank you