Nadia Boulanger commented on the paradoxical character of Francis Poulenc by saying that "one could meet him as easily in fashionable Parisian circles as at mass." For Poulenc, the contrasting worlds of the cabaret and the sanctuary are melded into one. The fantasies of being naughty in an innocent way and being innocent in a naughty way are fulfilled in the best of his music.

The light humor of the cabaret is, in general, especially present in the instrumental music. The concerto for two pianos and orchestra, for example, is a romp through the fashionable clubs of Paris and the fashions of music history, where the slow movement of Mozart's Piano Concerto #21 is woven into a light-hearted tune he could have heard while having a few drinks. (Not even P.D.Q. Bach is funnier.) Sudden key changes, off-key notes, and musical non sequiturs furnish much of the humor in these works. The sonata for flute and piano flows with melodies so lovely that it would take a mean spirit to inquire as to whether they have anything to do with the meaning of life. It seems that the very lack of effort to express anything through music makes the lyrical themes, in their contrast to the rambunctious material, so haunting. In his ballet, Les Animaux Modèles, the central piece is a dance by Death and the Woodcutter where the music's relaxed charm vaporizes death. Death, however, becomes much more real in the Élégie for Horn and Piano, written in memory of Dennis Brain, where the horn begins by stuttering out a twelve-note theme before moving into a lyrical song of resignation. In the oboe sonata, one of his last work, the specter of death has come very close to him and the cheerful music takes on a longing for life beyond the grave.

Poulenc's opera Dialogue des Carmélites and his sacred choral music illustrate the serious extreme of Poulenc's music. The Christmas motet O Magnum Mysterium begins with a hushed entry to rivals the primordial silence of Victoria's great motet. The theme sung by the sopranos transforms a ballad-type tune into an expression of rapt religious devotion before the Christ Child. The Lenten motet Vinea meum electa takes an even lighter musical figure and fills it with the heartbreak on Jesus' part when the crowd chooses the release of Barabbas instead of him. Time seems to stop when the formerly comical key changes keep the Salve Regina musically rootless and thus resting in the palm of God's invisible hand.

In Poulenc's musical mansion, not only are there cabaret rooms and chapels, but there are rooms that combine the two. Sometimes it is something like a two-ring circus where the chorus line performs in one and the altar is placed in the other.

The Concerto for Organ, Strings and Timpani in G Minor begins with an outburst that reminds the listener of the Fantasia by J.S. Bach in the same key. By turns, the solo instrument sounds so much like a theater organ that one expects to see a beer barrel roll across the floor any second and other times, it has suddenly been whisked into the church where it plays with hushed reverence while the faithful receive communion. The Gloria opens with a fanfare and then slips into a song and dance routine that the listener is sure was stolen from a Broadway musical. And yet the following movements that feature a soprano soloist who quickly makes one forget what is gone before in the sweep of the religious passion with which she sings.

Perhaps the most interesting rooms in Poulenc's musical mansion are those where the chorus line and the altar are mixed together on the same stage. For all the incongruity, everything seems to work together in one cock-eyed musical universe.

The Sonata for Two Pianos opens with a cascade of crashing chords that establishes an aura of solemnity, which is confirmed by the emerging theme which retains the same triple rhythm. The two fast movements have the usual capers of the cabaret, but in both cases, the merriment quickly dissolves into slower, lightly serious contrasting section. The Andante movement marches briskly but with sufficient solemnity that the out-of-tune notes are more expressive than funny. The coda to the final movement heralds a return of the opening figure so that it is the cascade the rings most in the ears of the listener. This sonata is one of those rare works where the musical ideas are so transparent that they are easily grasped on a first hearing, and yet the emotional juxtapositions draw one back to listening to it again many times without loss of interest.

The Mass in G Major features both the liturgical formality and the wit of Igor Stravinsky. The Kyrie is not a plea for mercy but a proclamation of God's mercy. The Gloria lumbers along with musical lines that could almost be sung in a musical, but not quite. I don't find this music to be quite an outburst of joy, but its positive tone is unmistakable. The Sanctus is one of Poulenc's most remarkable moments. One feels that the sopranos and altos must be dancing across the sanctuary as they start up with their simple and light-hearted tune. And yet, subtly, there is just enough weight to the music than one can detect the angels who are invoked by the priest during the cue for the Sanctus. The Soprano solo of the Agnus Dei soars up to the stratosphere where the unshakeable peace of God of hovers over the whole world.