Adjacent to the modern 9-foot maple-wood grand piano, the much smaller pianoforte surely feels inadequate, and with reason. The elderly keyboard has been undervalued since the 19th-century desire for bigger, louder and faster ushered improvements preferred by Romantic composers and beyond.

But for pianist and Moores School of Music professor Timothy Hester, the instrument has a prominent spot in his Kirby-area townhome living room away from the black monster which invades the otherwise dining area.

When Hester sits to polish a trio of Mozart concerti, he dominates the instrument and hovers over it as if it were a plaything. At first, the fortepiano's frail legs seem they could give way in an instant.

But surprise! The musical little engine that could can endure quite a beating and responds sensitively to Hester's musical ideas. Moreover, his interpretation involuntarily adjusts to the fortepiano's organic temper tendencies — even affecting fingerings to change.

Mozart on the fortepiano is much different than Mozart on the grand.

That's the muse behind Hester's Tuesday night concert titled "The Amadeus Project: Bringing the Past into Focus" at Moores, where he will amass an 18th-century 30-piece period style orchestra with musicians from Amsterdam, Wisconsin, Massachusetts, Washington State and Texas, and from early music ensembles including Ars Lyrica and the Cambini Wind Quintet.

"As a performing musician, I gain much perspective shifting between the instruments," Hester tells CultureMap. "Even with the shallow depth and reduced range of the fortepiano, there's unlimited nuance potential."

From the fortepiano, Hester will conduct and perform Mozart's Piano Concerti in A Major (K.414), G Major (K. 453) and C Minor (K. 491). Leading from the keyboard is something Hester has never done.

For listeners, the trio of showpieces chronicles Mozart's compositional growth as he expanded his orchestra with bolder instrumentation, widened his chromatic language, weaved accompanying and solo instruments in rich dialogue and challenged the conventions of structure. The pinnacle is K. 491, one of two concerti he drafted in a minor key and hailed as the greatest of the 27.

How the instrument differs

This fortepiano, on loan from UH, is a replica built by Belgian atelier Chris Maene from plans drawn by German-born Anton Walter (1752-1826), a maker of distinction, who Mozart bought an instrument from in 1782. When Mozart crafted the A major concerto that fall, the G major in 1784 and the C minor in 1786 — the latter two penned for himself to perform in Vienna — it was the sound of this instrument he was accustomed to.

Unlike the grand piano's iron frame cast, which holds roughly 18 pounds of pressure from steel strings, the fortepiano is all wood. The dampers are covered with leather instead of felt. The keys are slightly smaller, though as Hester says, "it can take a lickin'." The two pedals are located underneath the sound box and are operated by the knees. On the grand, the feet get that workout.

"When using the una corda pedal on the grand, it's an all or nothing kind of thing," he explains. "In the fortepiano, the effect is achieved using a piece of cloth. The mechanism allows as many gradations as the performer can execute."

The lower tessitura is growly while the upper register has a sublime sweetness. With louder dynamic ranges, the attack is accompanied by metallic overtones.

Perfect pitch? Give me an A

If the tuning sounds somewhat "deflated" to contemporary ears, it is because instruments in the 1700s weren't designed with 20th-century standards in mind, or any established convention other than what was regionally customary. Most American orchestras use 440 Hz to identify A above middle C, some prefer a shaper more brilliant sound at 442 Hz, while a few European ensembles have adopted a pitch center upwards of 445 Hz.

For the Amadeus Project, the A will drop to 430 Hz.

"The A=440 pitch standard is a 20th-century invention, just like standardized spelling and languages," Matthew Dirst, UH music professor and Ars Lyrica founder, explains.

"Pitch was formerly a very local phenomenon and could range from very low (in France) to very high (in Italy). A=430 is simply the best guess about Vienna in the late 18th century, based on the dimensions of surviving instruments from the time."

Mozart was deliberate when assigning key centers, reserving certain modalities to achieve specific affects: Think D minor in Don Giovanni and the Requiem, A minor in Rondo Alla Turca from the Piano Sonata No. 11, K331 and E-flat major in Magic Flute as a symbol of Masonic myth.

When using a modern scale — and a latter-day grand piano — are Mozart's intentions lost in translation? That's what Hester hopes to bring into focus.

"The Amadeus Project: Bringing the Past into Focus" is set for 7:30 p.m. Tuesday at University of Houston's Moores School of Music. Tickets are $15 and $10 for students and seniors and can be purchased at the Moores Box Office and by calling 713-743-3313.