Imagine you're at a classical music performance. Everyone -- audience and orchestra alike -- is dressed for the occasion. As the lights dim, the crowd settles down. Onto the stage walks the evening's soloist, carrying his iPad. He sits down, turns the iPad on, and begins to play.

In a setting that tends to feel old-fashioned if not timeless, an iPad may appear out of place. Many audiences laugh or chuckle politely as performers swipe the screen to turn the page (a Bluetooth-enabled page-turning foot pedal also exists). But get used to it: The iPad and centuries-old musical scores are an awesome combination.

For musicians, the iPad has three great advantages over paper scores: cost, ease of transport, and, most of all, access. The first two are straightforward enough -- PDFs of public-domain music are cheap (i.e. free) and light (i.e. weightless). But the benefit of access is not as intuitive, and is largely because of a wiki called the International Music Score Library Project (IMSLP) started by a then-18-year-old conservatory student in 2006.

Through an app called Padrucci (a mash-up of iPad and Petrucci, an early-16th-century music printer), musicians can access the more than 100,000 scores users have uploaded to the IMSLP from libraries and private collections around the world. Many obscure works, available only in small music repositories in Europe, can now appear on your iPad in seconds. Additionally, some of the files are scans of the original composer's handwritten copy. For musicians who have spent years studying the works of a beloved composer, to play from the original (albeit a digital version), can be thrilling.

Below, a performance of Chopin's Prelude in E minor: