On any list of "Jazz for Beginners" you'll see Blue Bossa, and right off the bat, in the fourth measure, The Real Book has an unlikely Bb7 chord. Most jazz musicians I've spoken with use the changes Cm7 / Cm7 / Fm7 / Fm7 for the first four measures, instead of The Real Book's Cm / Cm / Fm7 / Bb7. I'm not sure how that Bb7 got there, or how it's stayed there after 50 years, but there it is.