Frequently Asked Questions

Q. When can I buy your recordings?
A. Our immersive new recordings of Glenn Gould's playing of his 1955 Goldberg Variations on the Sony BMG Masterworks label are widely available now. Order a copy by clicking on the store link on the right.

Q. What's next?
A. Our next album is Piano Starts Here, played by the great jazz pianist Art Tatum. This includes his first four studio recordings from 1933 and the live "Just Jazz" concert from 1949. Sony recorded the re-performance before a live audience at Los Angeles' Shrine Auditorium (the original venue) in September 2007. Their new hybrid multichannel SACD/CD is scheduled for release in June 2008.

Q. Where can I hear a re-performance in person?
A. Click here for the current schedule. We always welcome visitors to our superb lab and recital hall in Raleigh, North Carolina. Contact us for an appointment, if you are in the area.

Q. I have solo piano albums I'd like to hear re-performed. How do I let you know?
A. We have a couple of feedback forms. Consider picking albums with "great playing, but poor sound."
- For jazz albums, click here.
- For classical albums, click here.

Q. What's a re-performance?
A. A good question, since it's central to what we do. Click here for a thorough discussion.

Q. Splices – how do you handle splices that are audible to the ear?
A. In our current work, we’re only looking for piano notes with their unique signatures. Clicks, scratches, coughs, birds, and so on don’t match our signatures for piano notes, so don’t make it into the second round of processing.

We have observed that tempo mismatches in splicing can become a bit more evident when heard live. There’s a clear splice in the Gould 1955 Goldberg Aria, where from one note to the next, starting on a measure line, the tempo is ever-so-slightly faster. It doesn’t change gradually, it occurs instantaneously from one note to the next and then onward. To our ears, no human pianist could play precisely like that, so it must be a splice. Also, the quality of the background noise changes slightly at that point, although there isn’t an accompanying tick.

Q. Live Recordings – are background noises – coughs, sneezes etc – any problem?
A. No. Audience noises structurally don’t have the characteristics of a piano hammer striking a string, so they’re invisible to the process. We don’t make any attempts, of course, to re-insert those noises in the re-recording, since our focus is solely on piano note and pedal re-creation.

Q. Compression – most recordings are issued with various amounts of compression, much of it dictated by the format originally designated for release – material issued on LP usually had more compression than material on CD. Some compression is on the actual master tapes. Will the equipment know how much compression was done so that the ratio of high to low is restored?
A. We do not have this step automated, and it’s a place where we apply our professional and artistic judgment. As an early processing step for each re-performance, we have an experienced professional pianist evaluate what the dynamic range should be: if this piece were performed on this piano today, how loud and how soft would it be?

There’s another aspect to consider, which is “gain riding.” Was the volume or compression changed in the midst of the recording? Today, we’re not doing anything to compensate or change our results, although we think we can detect it reasonably reliably. A decrease or increase of recording gain scales down the overall power of the signal, yet leaves the timbre of the piano tone intact (if they didn’t fiddle with individual frequency bands). Since we’re able to analyze the relationship among the harmonics of the piano tones, we’re able to tell the difference between a note being played softer or louder and a gain change. Fortunately, use of gain riding is somewhat more prominent in orchestral or opera music than in piano recordings.

Q. Source material – is it more desirable to go back to the original source material, or use CD masters?
A. For all our efforts, we truly want to go back to first sources on material. Dynamic range, speed stability, harmonic accuracy, and correct timbral balance are important in making informed decisions about the original performance.

Q. Where does the name Zenph come from?
A. Zenph is a purposeful misspelling of the German word for mustard: Senf. Short, sweet, pronounceable, and reasonably unique in Internet searches. We also liked the business model of the mustard plant, which grows strong from a tiny seed. In our logo are two musical notes, a D leading to an A - our shorthand for Digital back to Analog.

Original Performance, New Recording!