If you can write a twenty-minute-long opera, you can move on to an hour-long opera. And if you can write an hour-long opera, you can write a full-length work. This is the premise behind the Washington National Opera’s American Opera Initiative, which went out of the gate in 2012 with an evening of three short works, and continued with an hour-long work — Approaching Ali, by D. J. Sparr — the following spring.

Now, midway through the second season of the program, WNO has announced the composer-librettist team for the third hour-long work, which will be presented in early 2015: Douglas Pew and Dara Weinberg. The two are evidently following the company’s prescribed course for composer-librettists: together, they created one of the first 20-minute operas, “A Game of Hearts.”

Their upcoming opera, “Penny,” is an original story about a woman with a disability and a talent for music (Susan Boyle, anyone?). It will have a workshop later this week (not open to the public), and have its official premiere in January, 2015 at the Terrace Theater.

In commissioning smaller-scale works, WNO is certainly following a nationwide trend: more and more, smaller companies and smaller venues are acting as a fertile breeding ground for interesting new work. In Washington, Urban Arias is making a stalwart case for short contemporary opera; in New York, the Prototype Festival will hold its second season of new music theater in January, while Opera America’s New Works Forum will feature a range of work including, coincidentally, “A Game of Hearts” in January.

Whether writing short opera is good training for writing longer opera remains open to question. There are writers who are more adept at short stories, others at sprawling novels; just as there are composers who express themselves best at shorter lengths (Webern and Wolf come to mind) and others, like Wagner, who take 16 hours. Running a 100-yard-dash is not a priori the best training for a marathon. On the other hand, thrusting a talented young artist into the spotlight with an evening-length commission on a major opera stage is not always the best use of resources either (witness Nico Muhly’s recent “Two Boys” at the Metropolitan Opera). The bottom line is that encouraging new voices and new work is a good thing, and that the Washington National Opera is now in its third year of a program that is getting more music heard. Let’s applaud it — and attend it. The second hour-long opera in the American Opera Initiative, Huang Ruo’s An American Soldier, will have its premiere this coming June.