This superb and much-played (by me) CD is exactly what its title says: "A collection of classic tracks from the softer side of Miles Davis". It's 100% instrumental, with Miles' expressive trumpet playing actually taking over the nominal vocal line in many numbers and so incidentally demonstrating his virtuosity through a wide range of moods and styles.
Miles admitted later in life that he had "always loved playing ballads" but rarely allowed himself the luxury of doing so onstage, where he constantly pushed the envelope of experimental jazz to new levels. "Mellow Miles" showcases many of his more melodious numbers taken from "Kind of Blue" plus several excellent covers including: "Bye Bye Blackbird," Gershwin's "Summertime" taken from the "Porgy and Bess" collaboration with Gil Evans, and Porcaro & Bettis' "Human Nature" which many people associate with Michael Jackson.
This collection is a perfect introduction to Miles Davis' great trumpet playing and can be listened to anywhere, anytime with a keen ear, or alternately used as high-quality background music where its melodious ambient sound will not be too intrusive. If you have it in your collection, it's the kind of album you will play again and again, and then again, for years and years. In fact, it's outright brilliant.
Even if you think you don't like jazz, give it a listen: you may like it, and be tempted to move on to the more innovative and demanding stuff (if so, try "In a Silent Way" next).