In Symphonic Fantastique, Berlioz utilizes an idée fixe, a theme that appears in all five of his movements and lends unity to the piece as a whole. As I listened to Symphonic Fantastique, I saw Berlioz’s idée fixe as representing a combination of operatic leitmotifs and the ritornellos or thematic repetitions composers used in sonatas. While leitmotifs were a way to remind the audience of a particular person or object, sometimes prompting subtle connections or links between the action in the drama and the theme being played, the idée fixe was also a way for Berlioz to represent Harriet. Moreover, just like composers repeated themes (by variation, fugue, development) to unify the movements of their symphonies, Berlioz, too, repeated the idée fixe in his five movements.

Yet, Berlioz not only combines the operatic leitmotif with the symphony’s repetition of themes, but he takes these tools a step further by varying them and complicating them in each movement. Because there is no physical presence of Harriet for us to see on stage, he must mold her idée fixe in each movement to convey how she changes or how his feelings toward her changes. The change of the idée fixe is the means by which he communicates the plot to us.

When he initially presents the idée fixe in the first movement, he uses the flute and strings (5:08). The idée fixe sounds mellifluous and homophonic here, and our introduction to Harriet is soft and warm. Even within this movement, however, Berlioz experiences emotional change with respect to his feelings for this woman. At 7:41, the idée fixe is already presented differently. Here, I feel an escalation and tension, conveyed through a more dramatic crescendo than at 5:08. Moreover, while the staccato sound of a string instrument is present in between the first idée fixe melody at 5:11 and 5:17, it does not overlap with the main melody. In contrast, in the idée fixe at 7:41, this same strings sound overlaps with the idée fixe, and another texture is added on top of both of these at 7:58. The idée fixe here is polyphonic and busy, thus sounding more tense than its earlier counterpart.

At 2:04, in the second movement, we hear the idée fixe once again, and while it begins slowly and calmly as before, it is then quickly complicated by the addition of overlapping instruments at 2:17. A deeper wind instrument dominates the idée fixe melody here, as opposed to the softer sounds of the strings and flute in the first movement. Thus, while a tenderness does remain in Berlioz’s view of Harriet, I sense a tension through the deeper, overlapping sounds, as well.

In the third movement, the same idée fixe returns, but is punctuated by sounds of a dissonant, dark affect.  At 7:12, we hear a solo instrument gently produce the idée fixe, but this is quickly interrupted at 7:17. At 7:24, the soft idée fixe returns, but is interrupted once again at 7:30. This sort of back-and-forth between the soft idée fixe and the foreboding, harsh sounds that interrupt it continues until 7:37 when they both overlap, generating simultaneous, conflicting emotions in me. Finally, however, the dark sounds take over and drown out the pleasant idée fixe around 7:57. Berlioz hence creates a struggle between the idée fixe and a darker melody, and by allowing the darker melody to prevail, he communicates a plot to us through his music. We are able to tell that a darker side to his love has emerged.

In my opinion, the use of the idée fixe is most dramatic in the fourth movement. Here, we do not even hear the theme until the very end at 4:11, and it is almost immediately interrupted by a large, dramatic orchestra. This orchestra completely drowns out the solo instrument that was playing the idée fixe a split second before. While we see the idée fixe engage in a back-and-forth struggle with the darker sounds in the third movement, here, in the fourth movement, there is no struggle. The idée fixe does not “fight back.” It is as if all hope is lost.

After the crash that ends the fourth movement, the entire nature of the idée fixe is transformed. This manifests in the fifth movement. In this final movement, at 1:47, we hear the idée fixe again. However, it no longer flows seamlessly and gently as it does in the first movement. Instead, it presents as an odd, punctuated sound. Thus, by the time we get to the fifth movement, we have seen the melody of the idée fixe go from a pleasant sound to engaging in a struggle with darker, more dissonant sounds, to getting overpowered by these darker sounds, and then finally being forced to change form in the final movement. Through the idée fixe, Berlioz creates the plot of a love story and, for me, completely reinvents and revolutionizes the use of leitmotif and sonata-like devices.