Summer in the Valley means musicals. With the major local theater companies mostly on hiatus, and the opera, symphony and ballet seasons finished by mid‑June, the hot months leave us a diet long on sweets. Between now and September you have the chance to view a lineup as varied as “Wicked,” “The Best Little Whorehouse in Texas,” The Who’s “Tommy,” “Beauty and the Beast,” “I Do! I Do!,” “Oliver,” “Bye Bye Birdie” and, not once but twice, “Joseph and the Amazing Technicolor Dream Coat.”

Time was, a musical meant a story told onstage in song, dance, and dialogue–all of it original. When people lined up to see “South Pacific” or “My Fair Lady” or “Fiddler on the Roof,” they expected (and got) new songs. Today, a musical can be virtually anything on stage with music in it. “Eubie!” and “Always Patsi Cline” tell stories, but the stories are nothing more than biographical sketches, excuses to perform the familiar, pre‑written songs of those artists.

I keep waiting for opera to experiment with this idea. Imagine the opera “Joe Green!,” a compilation of arias and ensembles from the operas of Giuseppe Verdi (“Joe Green” in English) tracing the life story of the great 19th century  master. Or maybe “Always Rossini,” with scads of those little patter songs that made the composer of Barber of Seville a household name almost 200 years ago.

Somehow, it’s not the same. Opera maintains its relationship to story, while the musical has become a much looser genre, a catch‑all for song‑and‑dance entertainment.

For information on all the shows mentioned above, check out www.showup.com and click on “theater.” The popular Web site is a place to find show and concert details, and even to buy tickets.