A great many works of music exist in multiple versions, for orchestra and for piano (or two pianos)—in fact, one can think of such works as quite an extensive sub-genre. Liszt’s many symphonic poems, the Rite of Spring, and Ravel’s La valse (which has versions for both one and two pianos) are just a few examples of “hybrid” works. Some are known almost exclusively as being either a piano or an orchestral work (such as the Rite of Spring), others are widely known in more than one version (Brahms’s Variations on a Theme by Haydn, for example). Besides the display of virtuosity in playing an orchestral piece alone at a keyboard, there are many qualities that are easier to convey at the piano then with an orchestra, especially a large one, as is often the case in these works. The piano has more rhythmic flexibility than a conductor has, so although a great conductor can produce convincing rubato, the pianist will always possess a degree of spontaneity that the conductor lacks. On the other hand, the orchestra naturally has countless advantages over the piano.
A curious example of a hybrid work is Barber’s Souvenirs, a collection of six vignettes in the form of salon dances. The work exists in versions for orchestra, solo piano, and four hands. I discuss here the hauntingly beautiful third movement, Pas de deux, explaining why I believe it works better as a solo piano piece. On a conceptual level, a piano can likely better convey the intimacy of two dancers than an orchestra. Even visually it makes more sense, as one would need only to add one more person to the stage to get a proper Pas de deux, rather than subtract most of the orchestra. But much as I like the orchestral version, I believe that it is actually Barber’s orchestration that best makes the case for the piano version. The orchestration is lucid, colorful, and transparent, and relies greatly on the flute, oboe, and clarinet to carry the melody (naturally, a single wind instrument creates more of a sense of individuality than a whole string section). That said, it does leave some almost unavoidable gaps in the long and soaring phrase. As the melody passes from one wind instrument to another, there is an inevitable sense of “friction.” On the other hand, the solo piano version allows us to imagine the orchestral scope of the work, with full use of the wide register of the piano, without breaking the thread of the lengthy melody. Thus, we get the expansive nature of the music and retain the intimacy of a dance for two. (The issue of scope is one of the reasons I believe that La valse works better as an orchestral work than on the piano. The orchestra can “overwhelm” better than the piano, regardless of the pianist.) In addition to all of this, we pianists benefit from extra rhythmic freedom by playing the two hands not exactly together at times, a technique nowadays considered a bit old fashioned, but one that pianists such as Paderewski and Horowitz (along with countless others) often employed. This is something quintessentially pianistic that would not only ideally suit the supple character of the Pas de deux, but also perfectly correspond to the salon character of the Souvenirs. If so, should it be played on the piano in an “orchestral” manner, or not?