Look at it this way: When we think of the blues, don't we think of some guy wailing on an old beat up guitar in a smoky tavern with a bunch of people in jeans and T-shirts? When we think of classical music don't we flash on an ornate concert hall with a grand piano on high stick and a performer in tux and tails and women in sparkling evening gowns? Just the visual image alone makes it seem like classical music and blues are worlds apart.
The music itself is innocent of this visual diversity. The music is made up of chords, melodies, harmonies, counterpoint, dynamics, articulations and rhythm. It doesn't know about smoke-filled rooms, blue jeans, or tuxedoes. It doesn't rely on ushers passing out programs or a society passing out dress codes to fit with a particular genre. The music is blind. All it cares about is having a wonderful time.
Once a radio announcer who was obviously a classical music fan confronted me on the air and stated that blues is a lowly form of music whose text is relegated to the gutter with stories of loose women and booze and etc. ... and sometimes you can't even understand the words. Then he asked the question; "What do you think about that Mr. Siegel?" I answered immediately; "Opera! I rest my case."