Putting a ear to the past

Many aging musical instruments are too fragile to be played

By Monise Durrani
Producer, Click On

When a Scottish academic discovered a piece of 17th Century harpsichord music in a little known archive, he was keen to hear it played on the instrument for which it was written.

But bringing the music back to life proved a hard task for Dr Kenny McAlpine, a lecturer in computer arts at the University of Abertay in Dundee.

Antique musical instruments are incredibly fragile - some do not hold their tuning for long enough to play a piece, others are too delicate to play at all.

So Dr McAlpine decided to go for a 21st century solution - and make a digital reconstruction of an antique harpsichord.

The digital copy - a keyboard attached to a speaker and piece of hardware which stores and streams sound samples - may not be as attractive as the wooden antique instrument, but it sounds exactly the same as its antique counterpart.

Soft sounds

For his project Dr McAlpine used an antique harpsichord from Hospitalfield House in Arbroath.

There, with the instrument tuned for the process, Dr McAlpine set up microphones to record the harpsichord - recordings which would form the basis of his digital instrument.

However, he says, it was not enough to simply record the sound of each note.

One of the main motivations for this is to enable people to experience in a tactile way their musical heritage Dr Kenny McAlpine

"The interesting thing about the harpsichord is that there are characteristic idiosyncrasies of the instrument," he says. "Things like the sound of the keys as you strike them, the sound of the jacks and the plectra as they make contact with the strings - these are all things that tell you that you're listening to a real, analogue, organic instrument.

"And these are very often the things which are missing from digital copies of instruments."

On top of collecting all the sounds of the instrument, Dr McAlpine had to record each note several times.

"When you're playing an instrument, if you play the same note twice in quick succession, you never get exactly the same sound out of the instrument," he says.

Having the computer copy randomly select one of the recordings when the digital instrument is played helps to fool the human ear.

Play on

The technical development which made Dr McAlpine's digital harpsichord possible is disk streaming - the ability to retrieve and play audio which is stored on a hard disk in real time.

A faithful recreation involved more than just recording notes

"Previously instruments were restricted by the amount of RAM which a computer held" he says. "Nowadays with hard disks costing next to nothing for terabytes of storage you can really go to town and create levels of detail which even five years ago would have been unheard of".

The digital instrument, while not as elegant as its antique parent, does have some advantages.

"All of the tuning is controlled digitally, so not only does the instrument stay stable and in tune, it means that we can explore things like the difference between classical tuning and renaissance tuning."

The tuning of instruments has in the last 400 years been raised by about a semitone, and Dr McAlpine is able to switch between tunings simply by pressing a button, rather than having to manually retune an entire harpsichord.

The next step for Dr McAlpine is to use these methods to create more copies of antique instruments, and allow the public to "play" these historical instruments, which are otherwise out of reach behind red velvet cords.

"One of the main motivations for this is to enable people to experience in a tactile way their musical heritage" he says. "You'll be able to see the instruments on display, but then get your hands dirty, have a bash and a play and see what each of them sound like in turn."

Dr McAlpine also believes that consumers will benefit from developments in sound sampling.

"As technology becomes cheaper it becomes easier for manufacturers to use high resolution and more detailed models in their instruments," he says. "A lot of mainstream instrument manufacturers are now offering digital alternatives to their traditional analogue instruments."

He is keen to point out that both analogue and digital instruments have their place: "I think that the trick is not to see one as a substitution for the other, but to recognise that both have their strengths.

"I love the idiosyncrasies of my strung pianos but I love the convenience, portability and stability of my digital instruments. There's no way that I would take one of my antique instruments on the road if I was doing a gig, but I'm happy to sling a digital one in the boot of the car."

Click On can be heard on BBC Radio 4 at 16.30 on Monday 15 September 2008 and on Listen Again for a week after broadcast.