Chicago’s “definitely not about drugs” song, 25 or 6 to 4, is a rock/jazz track released in June of 1970. I’ve always found this song enjoyable and combining Jazz and Rock well. But again, it is definitely not about drugs.
You may recognize the song from Rock Band 3, or from covers by several prominent artists (including Earth, Wind and Fire). It made its way to #4 on Billboard’s Hot 100 and #7 in UK’s Top 100 as well.
Overall, I would rate the song a 9.5/10. I love the instrumentals and the combo of Jazz and Rock, though at times the track sounds a bit chaotic to me. It is a classic so of course, if you have not heard it, I recommend a listen: