This quote demonstrates the existence of three different preparations for this piece: the original preparation used by Cage at the premiere, the adaptation of this preparation to Jeanne Kirstein´s piano in 1969 [12], and finally, the one proposed in Peters edition of the score. Differences between them are abysmal, for example, in the version recorded by J. Kirstein there is no trace of weather-stripping, instead metallic materials are used in this version. In order to recreate, or at least to try the original preparation (1940), Vaes proposes to review the most contemporary preparation practices to Bacchanale. One of the conclusions he draws is about weather-stripping, the most common preparation: "it is unlikely that its original preparation table would have contained weather stripping" (Vaes, 2009, p. 725).
This issue, concerning the different options of preparation, could have been a difficulty around 1950 due to Cage´s opinion thereon: "very exact measurements must be made as to the position between the strings" and "in order to repeat an obtained result, that particular screw or bolt, for instance, originally used, must be saved" (Vaes, 2009, p. 724). However, over the years his attitude became more flexible and he opened up to new interpretations: "When I first placed objects between piano strings, it was with the desire to possess sounds (to be able to repeat them). But, as the music left my home and went from piano to piano and from pianist to pianist, it became clear that not only are two pianists essentially different from one another, but two pianos are not the same either. Instead of the possibility of repetition, we are faced in life with the unique qualities and characteristics of each occasion" (John Cage in Bunger´s foreword, 1981).
According to this, it would also be possible to find this technique in Bacchanale [8]. During the time of rhythmic structures, "section lengths were counted in periods, marked in the score by double barlines or by rehearsal numbers or letters" (Emmerik, 2009, p. 218). Looking at the score, it is obvious to place a first division or section from bar 1 to 9 (tempo "Fast"); the next section ("Faster") starts at bar 10 and ends at 15 (six bars in total); the third section would have only eight bars. The total count of measures per section is: 9-6-8-6-13-10-7-43-32-etc. It is not necessary to understand that a rhythmic structure based on the number of measures per section does not exist. In fact, rhythmic structures need bars of the same duration to work, whereas in Bacchanale, bars of different measures are alternated. Therefore, it is possible to assert that there are not rhythmic structures in Bacchanale.
At this point, it is worth remembering Bacchanale´s role as a music written for a choreography and as Emmerik says: "many of Cage´s works from the 1940's [...] employed structures that could be described as 'additive'. In most cases, additive rhythmic structures were used in incidental music for the dance" (Emmerik, 2009, p. 219). In this situation the structure was not determined by Cage but by the dance. "This is the case in Bacchanale (1940)" (Emmerik, 2009, p. 219). Even so, a detailed study of the structure shows that if we replace the measure bar for the measure beat (it is kept even if the measures change), it is possible to glimpse some of the mathematical structures used by the composer. At the beginning of the piece, all sections "Fast" have a total of thirty beats, while "Faster" sections have only twenty beats. From bar 60, these divisions become longer and more irregular, adapting to Fort´s choreography.
2.2. Compilation of alterations and effects
The table of preparations annexed to Peters Edition of Bacchanale shows three different types of mutes: fibrous weather-stripping, screw with nuts and small bolt. Cage did not specify the size of these objects, it must be the performer himself who experiments with them until finding the most appropriate solution. Even so, some pictures of the required materials are shown here with the purpose of helping the player [10].
Bolt and screw are two similar objects, particularly for those readers that are not used to hardware material. Apart from their different functions, there are also differences in the shape that distinguish them: both bolt tips are flat, one is designed to accommodate a nut and the other, to press with the right tool. On the contrary, one of the screw tips is pointed and is designed to penetrate directly into the material to be fastened. Curiously, Cage mixed both elements using a screw with nuts and a bolt without its corresponding nut. The number of nuts to be used together with the screw is again the performer´s decision.
2.1. Period and circumstances of composition
In chapter, 1.2 "The emergence of the prepared piano", the circumstances surrounding the composition of Bacchanale have already been discussed. Undoubtedly, this is an exciting story that predetermined certain requirements for the composition, but Bacchanale does not depend exclusively on the room available in the Repertory Playhouse. Information about the techniques used by John Cage at this time is much more relevant for understanding the piece.
One of the most remarkable aspects of Cage´s compositional technique during those years is the use of rhythmic structures. These structures were determined prior to writing anything, and later, he filled them with sound, noise or silence. One of the most used structures was the square root form. It is clear to see its use and development in First Construction (in metal) (1939), where the only structural exception is a nine measures coda, Second Construction (1940), where the microstructure rotates in each section, or Third Construction (1941), where the microstructure rotates independently in each performer.
Once the preparations indicated in the score have been understood, there is still a possibility to investigate more in depth:
"Originally I knew where the preparations for Bacchanale should be placed and what they were, and so I didn´t write them down. As time passed and I no longer played it, my memory faded, etc. When the piece was prepared for Peter, I tried it out on some piano (I haven´t had on of my own since 1954) and wrote down what I thought was o.k. Then when Jeanne made the recording, we had a different piano, and so made the preparation that seemed suitable for it." (quoted in Vaes, 2009, p. 723).
Another result of analyzing the score is that most of the sections entail a new tempo. However, these new tempi are not really precise metronomic indications. Tempi range varies from "Very Slow" - "Slower" - "Slow" - "Fast" - "Faster" - "Fast II", keeping an overall shape of the piece within the scheme Fas - Slow - Fast (A B A form). The ambiguity of tempi helps with adapting the music to the choreography speed.
For the same purpose of coordinating dance and music, the endings of each section allow some rhythmic flexibility. In general, the end of a section contains a monodic part, often accompained with a diminuendo and ritardando, that ends in a fermata, long sound or silence [9]. This fact gives freedom to vary the length of each section to fit the choreography. An exception for this rule is the "Slow" section (bar 132) which is a long accelerando towards the rhythmical re-exposition of the piece.
Dynamics remain fairly stable throughout each section, that is, a single dynamic for the whole section. This stability evolves towards a greater activity (dynamical changes in the same section) in the end, in the re-exposition of fast sections. In any case, dynamic changes always affect both voices (right and left hands) and have a subito effect. There are just a few crescendi, and the written diminuendi are always related to a section ending. The last fact to emphasize on the dynamics is the relation between slow tempi and soft dynamics, and, by contrast, fast tempi and loud dynamics (with slight exceptions in this second case).
From a rhythmic point of view, it should be noted that a work with an African inspiration and such evident rhythmic character has a regular rhythm based on eight notes, sixteenth notes and quarters throughout the piece. Nevertheless, this writing was characteristic of Cage´s early stage: abundance of regular rhythms that are suddenly interrupted by irregular rhythmic events. These elements are, for example: the quarter triple in bar 28 (reinforced by a louder dynamic), or eighteenth notes triples, sixteenth notes triples and doted sixteenth notes in the re-exposition of "Fast". Another element that breaks rhythmic regularity is the use of rhythmic motives that measure different from the bar in which they are written. In this way, polyrhythms arise between these motives and the natural bar rhythm. A final element of rhythmic variety is the use of same materials in different measures, for example, the characteristic sixteenth notes bass line (A-Bb) written in 5/4, 4/4, 3/4, 6/8.
Most preparations, excluding two, are weather-stripping bands [11]. This fact equals the timbre of the work in general. Thus, Bacchanale´s prepared piano sounds like an instrument with a defined timbre, instead of multiple timbres coming from the same source. This detail will be specially relevant in the next chapter 3. "Reconstruction Process".
Once the materials are known, it is necessary to place them in their exact position. Of course, it is known which pitch should be modified, but this still leaves two or three strings along its length to place the materials between. Cage only specified the small bolt placement on pitch F: between the second and third string at an aproximated distance of 3" (7,62 cm) from the damper. The indications are not so precise with the rest of preparations: it is always indicated between which strings the mute should be inserted, but not how far from the damper. It is important to notice that weather-stripping is always placed between the first and second string. This reinforces the idea of a common timbre to most of the piece. Once more, the distances between the mute and the damper must be found by experimentation.
High B-flat pitch is the only one with two preparations at the same time. As Vaes says: "triple-string notes can be used for two different kinds of sounds without changing preparations" (Vaes, 2009, p. 79). To achieve this effect it is necessary to use the una corda pedal (that shifts the hammers to strike only the second and third string). That is, high Bb usually will have two preparations, screw with nuts and wheather-stripping, and, in other occassions (Very Slow - bar 74 and Slower - bar 108), using the una corda pedal, just screw with nuts. The use of this pedal also affects high F pitch: "If only the second and third string of a triple-string chorus is prepared (e.g. by a bolt put in between them), the preparation pitch of those two strings will mix with the unprepared first string of the chorus. When depressing the una corda pedal, only the preparation pitch is activated" (Vaes, 2009, p. 79).
