Scrappy Bb aeolian scale, 11 tones ~ 440Hz. Made out off truck compressor vessel/tank.
 
 
About the scale:
In modern usage, the Aeolian mode is the sixth mode of the major scale and has the following formula: 1, 2, ♭3, 4, 5, ♭6, ♭7, 8. The Aeolian mode is the sixth mode of the major scale, that is, it is formed by starting on the sixth degree (submediant) of the major scale.