This is a flageolett sound played with plectrum on a steel-stringed acoustic guitar. I used this sound for coursera course "audio processing for music applications".
Mono clip of saxophone musician playing in a nearly empty square. Recorded using at shotgun mic & a beachman omni-mic. The echo of the sax can be heard as well as people walking and talking nearby. Sound clip is designed so that it sounds like you are passing the musician. Last half is the saxist playing in the distance.