I'm sure that each of us has experienced one of those moments. What, precisely, distinguishes live from recorded sound? It's a complex issue, but I'm pretty sure it has little to do with any of the measurable, quantifiable parameters objectivists obsess over. Fidelity must be a factor, but a lack of fidelity has never stopped any of my audio pals from hearing the difference between live and recorded music over the phone.
I remember one such incident from when I worked at Master Sound Astoria, a recording studio in Queens, New York. I was talking on the phone to a friend, who heard the sounds of a piano technician tuning the studio's instrument. My friend didn't know if I was in the studio with the piano, or if the sound of the piano was coming over the control-room monitors. I asked him to keep listening as I walked back and forth between control room and studio, and to tell me which was which. Without hesitating, he correctly identified the live sound of the piano, explaining that he could hear more of the studio's room sound over the phone. You can't get much lower-fi than a phone, but even so, it's not hard to tell the difference between a speaker reproducing the sound of a live piano and the real thing.
While visiting the Manhattan's Whitney Museum in July to see and hear the exhibition Christian Marclay: Festival, I heard the sound of a violin and piano from a few rooms away. My first thought was, The sound is too good for a museum exhibit; maybe it's live. Then I realized that the music was too loud to be purely acousticbut as I got closer, though still a room away, I also knew that it wasn't recorded, and that the music was coming from a sound-reinforcement system. Finally, I rounded a corner to see my hunch confirmed. I took a seat and listened to the remainder of Marclay's Ephemera, performed by violinist Mark Feldman and his wife, pianist Sylvie Courvoisier. The spiky music had a freewheeling groove, and Courvoisier made a fantastic variety of sounds by directly manipulating the piano's strings with her fingers.
Musing afterward about the experience, I thought it was the transient leading edges of the piano's and violin's sounds that had signified the "liveness" of what I heard. Granted, the music was played through microphones, amplifiers, and speakers, but it sounded absolutely live. Of course, a better test of "liveness" would have involved recording the music and playing it back over the museum's sound system. Would I still hear the difference? I don't know. Loudspeakers may be the least perfect, ie, most distorting link in the playback chain, but when playing live music, speakers can sound live. The quality of the speakers doesn't seem to play the crucial role; it's more about the mix, the room acoustics, etc.
At street fairs over the years, I've always recognized acoustic live music as the real thing, and there have been countless times when I've heard the sounds of live guitars, pianos, and singers coming from apartment windows, and never for a second thought the music was from a hi-fi. A violin, sax, trumpet, or steel drum played in a New York City subway station never fails to rise above the din. The live quality of music is a remarkably durable trait; we know it when we hear it.
I've noticed that the more distant the instrument, the less confident the listener is about whether the music is live or recorded. Perhaps the softening of transients plays a part; once they're gone, the differences between live and recorded music are more easily blurred. Depending on the instrumentation, live music can get pretty loudonly the biggest, brawniest hi-fis can deliver the full dynamic punch of a drum kit or orchestraso volume capability must play a role in the mystery.
I'm not claiming that hi-fis can never sound believably live, only that the factors determining fidelity are hard to pin down. A great live recording can sometimes get you almost there. Warren Zevon's Stand in the Fire (CD, Asylum/Rhino R2 101780), recorded at the Roxy in Los Angeles in 1980, always gets my juices flowing. Zevon and his band are in fine form, and hard-rocking numbers such as "Excitable Boy" and "Lawyers, Guns and Money" light up my Zu Essence speakers with a vengeance. Cranked up to 100dB, the Essences sound more or less like a good club sound system, but the CD's last two tracks, "Frank and Jesse James" and "Hasten Down the Wind," are performed solo, with just Zevon at his piano, and they sound closer to being in the man's presence.
The thing is, the band tracks are dynamically compressed, the solo tunes less so. Compression is part and parcel of almost every commercial recording, and just about every live amplified concert. So unless you're a musician, or hang around musicians, or attend concerts of classical music, virtually all the music you hear has been dynamically compressed. That may lower the threshold of certainty about liveness for some folks.
In his "Listening" column in the August 2010 Stereophile, Art Dudley observed that 78rpm shellac records can sound downright "bloody" (footnote 1) when played through something as awesome-sounding as DeVore Fidelity speakers powered by Shindo amplifiers. And there you have it: The right mix of very old recordings and carefully selected modern components can unleash bloody realism. I'm not so sure that ultra-high-resolution recordings played through state-of-the-art gear necessarily pack the mojo required to bring the music to life. There's something going on. We just don't know precisely what it is.
Footnote 1: AD attributed the descriptor bloody to Stereophile's Stephen Mejias, who used it to describe the sound at one of John DeVore's Monkeyhaus parties.