Checking if a Tune is in Minor
It can be challenging to hear if a tune is just very bluesy (in Major) or in Minor. To check if a tune is in Major or Minor, play the following in 2nd Position...
2 3 4 = Major - The 3 draw is the defining note. If it matches, then it's Major
2 3' 4 = Minor - The 3' draw is again the defining note. If 3 sounds real bad, but 3' sounds really good, then the song may be minor. The reason why I say "may be" is that if one of the musicians is playing the same notes as your 3', then the tune could be in Major, but the influence of that musician's note may lead you to a wrong conclusion that the entire tune is in Minor.
The next step is to try the Major Pentatonic Scale. Listen carefully to the B (3) and E (5+) notes... if they match well, then you're in Major.
Major Pentatonic Scale = 2 3" 3 4 5+ 6+
Now try the Blues Scale. Listen carefully to the B-flat (3') and F (5) notes... if they match well, then it's a strong indication of Minor. If it's in fact not in Minor, it doesn't matter, if you stick to this Blues Scale you're safe (it works for both).
2 3' 4+ 4' 4 5 6+