Far more common is poor relative pitch. This can be trained into a person, and is a great deal of work. If English was more dependent on pitch slides (we use it to denote questions vs. declarations and to denote stresses on words; there is subtlety possible but pitch slides are not necessary to communicate in English), there would be few of us with pooor relative pitch. I’m a music major, and I’ve noticed that those raised speaking East Asian and Pacific Island don’t have any trouble in sightsinging classes. It may be that they are sons and daughters of hard work and determination, but it may also be the fact that pitch slides actually determine the word being said. In… stink, now I can’t remember. Perhaps Cantonese… the (oo) sound is an entirely different phoneme when it is slid up vs. when it is slid down.