Sweet Emotion from Aerosmith's 1975 album "Toys In The Attic" was actually their first top 40's hit and became a really popular song. It's got a very classic and standard rock feel, shifting between the D and A chords that it's based on. There's an accompanying A minor pentatonic scale that fits into the song in the form of single string riffs. Joe Perry uses chromatic leading tones in his riffs to emphasize the target note, since leading tones provide that moment of dissonance before the resolution. In the solo there's also a lot of sliding double stops which give it a great country-blues feel.