Suites often feature contrasting parts and there’s certainly contrast to Boston Ballet’s “Parts in Suite”—itself serving as the company’s spring modern-ballet alternative to concurrent classical story entry Romeo and Juliet, which opens Thursday.

Running through April 9 at the Opera House, “Parts in Suite” takes a spin through three pieces by contemporary choreographers, presenting distinct differences in style, tone and especially music. With an empty orchestra pit, the music’s left to either onstage player(s) or a recorded soundtrack—and in this program, both.

Jorma Elo’s opening Bach Cello Suites sets a dark, serious tone, with cellist Sergey Antonov playing with precision at one corner of the stage, first spotlit alone and then joined by pairs of dancers who match the graceful flow of his cello. To one slow, sonorous section at Thursday’s opening night, Lia Cirio wrung extra emotion from her stretched limbs in push-and-pull exchanges with partner Paulo Arrais. And when couples joined in angular, crisscrossed formation near the end, they mirrored a trellis-like grid that hovered and sporadically tilted overhead.

The company premiere of Justin Peck’s In Creases breathed fresh air in the middle slot, not only in its carefree tone—with ballerinas rocking back and forth en pointe, then later rolling on the floor while the male dancers jumped across them like tires at a football practice—but its breezy 15-minute length. That levity echoed Philip Glass’s brightly repetitive Four Movements for Two Pianos, with company musicians Freda Locker and Alex Foaksman neatly interlocked—and even providing an interactive rest stop for dancers to lay hands on pianists’ shoulders. Peck and Mark Happel’s costume design lent a misstep in the men’s unflattering two-toned outfits, casting them like sailors in lumpy muscle suits.

The Boston Ballet debut of William Forsythe’s Pas/Parts, updated since its 1999 premiere in Paris, dealt an even sharper contrast, the off-white walls of its wide-open rectangular stage space splashing with color to whistles, clanks and even the sound of buzzing bees in Thomas Willems’ often jolting electronic score. And even denser than the sound waves were the paths of company-wide dancers, moving in overlapping traffic patterns of solos, duets, trios and ensemble turns that—like the music—grew less regimented and more graceful and free-spirited.

Nonetheless, that choppy closing piece, like the Bach Cello Suites at the start of the evening, approached 40 minutes in length. After a night filled with swoops and pirouettes, it got to the point of overload, no matter how sophisticated and well executed the dancing was—and regardless of whether the listener could smoothly transition from Bach to Glass to electronic noise.