One major physical characteristic of the steel pan that is observed throughout each period of development and that is still quite present today is the manner in which the placement of the outside notes and the overall design depends upon lines that radiate outward from the center of the drum to the rim of the drum, dividing the space. This physical characteristic is demonstrated at all levels of steel pan manufacturing and tuning since the early thirties to the present time. The geometric pattern that results from connecting the center point of the drum to measured points along the radius of the drum is quite evident in all the configurations of each of the different styles of steel pan. We can safely assume that this form is a permanent physical feature and as such is to be considered a major characteristic of the steel pan.

“From Convex to Concave” can describe one of the major turning points or gateways to modern steel pan construction and describes another physiological characteristic. From the very concept of creating a steel pan through trial and error to the present day steel pan, the sinking of the drum head still remains the main form of preparation in the building of all the voices of the steel pan family. It is important to understand the logic and reasoning behind the acceptance of concave construction over convex construction and how this came about.

During the early years, the introduction of metal containers allowed for vigorous rhythms played continuously by each player with a stick or a crude wooden mallet. Bear in mind that the containers were designed to carry products such as butter and cooking oil (or sweet oil as it was called.) The weight of the material that was used for these containers was of a very light quality tin.

At this time there were no exact pitches on the containers and the band depended on the twisted and distorted areas that were produced by the player’s continued striking of the drum’s surface for sound. As the players struck the drum to produce the desired rhythm, the soft metal containers would buckle under the pressure and would sink inwards causing the player’s stick or mallet to come into contact with the rim of the drum. As a result, the stick would sometimes break. To avoid breaking sticks it became quite natural to turn the pan upside down and push the surface back up to its previous position which would renew the area for continued playing once more.

With repeated displacement of the surface area it became noticeable that the pan would become warped. This caused the twisted surface of the drum to produce different sounds. In the years that followed, developing steel bands adopted this convex method of shaping the top of the container and for the first time pioneer pan tuners deliberately attempted to place definite pitches on the surface of the drum. Quite the reverse of what we have today, the convex surface was pushed upwards causing the entire area to form a type of dome. Dents were randomly placed on the surface of the dome and, depending upon the rudimentary pitches that were acquired by this method, parts of the scale could be recognized and simple songs could be played. Winston “Spree” Simon is often credited with playing the first tune on this type of primitive pan.

Convex construction was the norm for most steel bands until the forties when a young innovator by the name of Elliot “Ellie” Mannette (lathe turner by trade) decided to reverse the playing surface from convex to concave. This led to the present construction that is evident today. For some time this idea caused widespread criticism. Derogatory names like “tub pan” and “basin pan” surfaced. Additionally, for some time it was taboo to have one of these styles of pans. This changed when it was realized that this concave approach to construction made it possible to have more space for note placement on the drum than before. The country’s steel bands embarked upon a quiet race to see who could place the most notes on a drum. The 45 gallon barrel became the drum of the future. For the first time, a full size 45 gallon oil/caustic soda drum was sunk inwards creating one of the first concave steel pans. Gradually, widespread acceptance of the concave method of construction followed.

During the late 40's, in the period of transition from convex to concave construction, and from smaller to larger drums, the method of sinking the drum also changed. Originally, the drum was cut from a full barrel with the desired skirt length, placed on the ground, and sunk with a piece of wood until the required depth or bowl shape was obtained. This left a large hole in the ground and a very rough surface on the area of the drum that was used in the process. This method of sinking the drum became the norm for many years. But, as trial and error would have it, around the mid '50's a more sophisticated manner and method developed. Instead of cutting the needed part off the top of a barrell with the right skirt length and then sinking it on the ground, panmen reversed the process and started to sink the drum first, using the whole barrel to support the work and keep it from collapsing, and then cutting it off to the desired skirt length. This more stable way of sinking encouraged the use of metal hammers which was not possible previously, allowing the surface of the pan to become smooth and hardened. During this time pan tuners took a more precise approach to the research and development of their instrument producing an era of more exact measurements and symmetrical shape in the instrument. This in turn led to the more permanent process that we have presently. By the early '50's the first chromatic pan was developed by Elliott (Ellie) Mannette in time for the Trinidad All Steel Percussion Orchestra (TASPO) to attend the Festival of Britain in 1951. Lt. Griffith of the Barbados Police Band, who conducted TASPO, is credited as the person responsible for making sure all of the voices of the steel pan became chromatic.

With this new approach tuners had more control of the surface of the pan, creating a sound board which was not previously possible. This combined with more space for note placement led to more separation of the notes. Tuners began to stretch the metal which led to even more space and, coincidentally, better sounding high notes. Tuners found that the repeated hammering hardened the surface. With the separation of the notes and the hardening of the surface came a method of grooving around the note by taking a wooden dowel to create an impression around the edge of the note to further isolate the vibration of that note from other notes on the working surface.

In summary, the change in the construction of the pan from convex to concave led to more space for note placement, better control of the working surface of the instrument, the creation of a soundboard for the notes, separation of notes, hardening of the surface and grooving of the notes. These are all basic elements of modern day construction of a pan.

It became critical in the construction of the steel pan, where all voices are made of the same material, to be able to control and distinguish the tone and timbre produced by each instrument. One method that was found to affect these properties was the length of the skirt of the pan. Another method found to control these qualities was the placement of notes within the pan.

Pan tuners discovered through experimentation that the length of the skirt of the instrument affected its tone and timbre. In musical and acoustical retrospect, the results the pan tuners arrived at make perfect sense. The length of the skirt must be long enough to accommodate the longest (slowest) vibration emanating from that pan. Therefore, the skirt of a tenor pan would be shorter than that of a guitar because the lowest note of a tenor pan is higher (faster vibration) than the lowest note of a guitar pan. A guitar pan, with lower notes, requires more skirt length for the longer (slower) vibration to act against the skirt of the pan before the audible sound exits the pan and is released.

Many of the discoveries made through experimentation by the pan tuners make very good sense when looking back at them through the lenses or viewpoint of traditional Western music theory. Placement of notes on the pans is one of these. Note placement had to accommodate ease and equality of playing as well as tone and timbre of the instrument. This includes not only the combination of notes on the pan but the placement of the notes against each other within the pan and, to some extent, the shape of the notes, and the size of the notes. The early pan tuners had an uncannily exacting musical ear. The final arrangement of notes within each of the primal voices of the pan family, arrived at through ear only, can be compared favorably with the application of musical theory. Briefly, the Tenor Pan and the Bass Pans are arranged in a circle of fifths. The Double Second Pans and Tenor Bass Pans are arranged in an augmented chord. The Triple Guitar Pans are arranged with each in one of the three diminished chords. This did not happen because of any musical knowledge but rather because of how the notes fit into and sounded on the pan.

Though all the primal voices of the steel pan family (tenor, double second, triple guitar, tenor bass, bass) are made of the same material and have a range of notes that overlap, each has an unmistakable timbre: C4 (middle C) does not sound the same on the tenor as it does on the double second or the triple guitar or the tenor bass or the bass. Just as a major chord sounds major no matter the inversion [root (1, 3, 5) first inversion (3, 5, 1) second inversion (5, 1, 3)] each combination expresses its special, unique quality of overtones. When Middle C is the lowest note and is arranged in a circle of 5ths as in the Tenor Pan, it has a different set of overtones than when it is set as a mid range note of the Doubles Second pan arranged in an augmented setting. The Middle C of a Triple guitar, in the upper range of the instrument arranged in a diminished chord yields yet another set of overtones and timbre. Thus, the arrangement of notes on and within the pan(s) is of great importance to the timbre produced.

During the period when pans made the transitional change from single pan to double or triple and larger sets, the major contribution came from the Invaders Steel Band. This was not by chance but by a combination of studied measurements and an understanding of the methods of construction-based principles. This approach was introduced after exhaustive efforts by the pan community to arrive at particular patterns and designs suitable for playing across the pan, from one hand to the other, as opposed to playing around the pan. Elliot Mannette, the leader of the Invaders Steel Band (known as Ellie to the steel band community) always talked about equal separation of notes and scales and the importance of balanced playing in all scales on all pans, not just the Tenor Pan. The Invaders were very fortunate to have someone as gifted as Ellie working with them. His experience working with metals and fine measurements as a lathe operator had a great impact on the entire development and construction of the pan as we know it today.

At this critical point in the development of the steel pan there surfaced many new ideas, some accepted, others discarded. Again, in the forties one of the new ideas that became permanent was the introduction of the chromatic scale by the same innovator who was responsible for creating the concave construction of the pan, Ellie Mannette. The newly chromatic format led to the widespread acceptance of the steel pan as a musical instrument. One of the main sources in the development of the steel pan became the Woodbrook Invaders, formerly the Oval Boys later to be known as the Shell Invaders, led by the same Ellie Mannette. Under Ellie’s guidance and leadership some of the first primary voices of the steel pan family were developed.

During this period different styles and designs of pans were introduced, many of which were rejected or replaced by another after a short while. The evolution of the pan was in high gear and what did not work was quickly abandoned. Individual steel bands of the era fashioned their own patterns or configurations of notes on the instruments. Tuners of the bands were the deciding factor as to note placement on the pans. This led to widespread diversity and from time to time changes were made to accommodate the playing of a particular song.

The steel pan art form underwent a metamorphosis that led to a critical upsurge of invention among most of the major steel bands, especially those who had become more musically sophisticated since the introduction of the chromatic scale. A large number of new voices emerged. With this emergence came the personalizing of steel bands caused as a result of the way these voices were used within the band. Bands were recognized by their overall sound depending upon which pan received the emphasis in the arrangement. For instance, City Syncopators (led by Philmore “Boots” Davidson) were noted for the emphasis being placed in the guitar section during their mambo arrangements. Casablanca Steel Band placed emphasis on the double second in their arrangements. You could tell one band from another by the difference in sound.

It was quite noticeable when bands began placing greater emphasis on how they sounded and became more aware of how in tune the pans were. These were times when bands boasted of having more arrangements as opposed to only sounding good because of how well the pans were tuned. This became a turning point in the development of the steel pan where more focus was placed on the tuning of a note rather than on just playing the pan. It was not long before many bands noticed the difference in the sound of the bands that had a particular kind of configuration of note placement on the instrument. This occurred mainly among the steel bands in the west part of Port of Spain that were influenced by the Woodbrook Invaders, the home of the first chromatic tenor.