During the levelling the playing surface of the pan is formed to its final shape. The levelling is done with the backing hammer and is quite similar to the backing. During levelling, each octave pair of outer-inner notes goes through four steps that are interlinked with each other: taking out the fat, flattening the grooves, final shaping, and adjusting the notes to be level with each other. The last step of the levelling is to smooth the surface of the whole pan.
The purpose of the levelling is to put the surface back to the shape it had before the grooving, see fig. 6.1. The levelling can be seen as a continuation of the backing, but it brings the drum further towards a properly shaped steel pan.
Shaping is an important part of the levelling. During the shaping the surface of the notes is formed to soft bulges and the surface between the notes is formed to an evenly curved basin.
Fig. 6.1 Levelling. Upper part of picture showing how the pan looks after the grooving and lower part the result after the levelling.
"Taking out the fat"- flatten the grooves
The grooving has made the surface of the pan look somewhat "swollen", kept down only at the grooves, see the cross-section in fig. 5.5. Now the surface between the notes has to be formed to a smooth concave shape again, leaving the notes standing up as smooth convex dents. This procedure is called "taking out the fat".
Begin working on a note pair, preferably the pair with the largest inner note. Hit the surface near the border of the inner note until it gets down level with the groove. When the surface between the grooves surrounding the inner note is flat, it is time to do the same around the corresponding outer note. Begin hitting down the "fat", first between the grooves of the inner and the outer note, and then gradually work further up between the outer notes. If the outer notes are separated by one groove only, the groove is flattened by hitting right on it and a bit up on each note, see fig 6.2.
When the surface between the notes is smooth, it is time to adjust the grooves down to the level of the surface between them. This is done by hitting a bit up on the note. This lowers the groove and makes it flat. The result of this procedure should be almost invisible grooves, seen only as marks in the metal. This is the critical point where the metal will burst if you have grooved too hard. Work around the pan at least once, adjusting all the grooves to be level with the smooth transition from the convex shape of the note areas and the concave shape between them.
Fig. 6.2 Regions for "taking out the fat".
Shaping of notes
When all the grooves are flat, you start to adjust the shape and height of the inner notes. Hit a bit further up on each note (about 2-3 cm) to shape it to a smooth swelling. Now the note is formed to its final shape and it is important that the result is a smooth surface without sharp indentions or unintended buckles. Small buckles have acoustic resonances that may affect the harmonics in an unfavourable way, thus making the pan difficult to tune. On the larger notes it is extra important to check that the arch is smooth and the dent curve extends over the whole note.
After the backing and the grooving, the outer notes will have sharp "edges" at the rim. The notes look somewhat like a triangle with the top cut-off, pointing at the centre. But the actual sounding note dents in a steel pan all have an elliptical shape, no matter what shapes the note borders have. For an explanation, see the chapter about note shape in the theory section. This means that the outer notes have to be re-shaped to something more elliptical.
This is done by sinking the part in the small area between the place where the radial groove stops and the rim. Begin by marking the parts that are going to be lowered, see fig. 6.3. Then use the backing hammer to make a smooth curve, ending off the dents softly against the rim, see fig 6.4. The surface should be lowered down to the level of the radial groove.
Fig. 6.3 Shaping of outer notes. The lower a part is sunk, the darker it is marked.
Work round the pan, shaping one note pair at a time, until the surface between the notes is down level with the grooves everywhere. A skilled panmaker often does this work in one round, because of the precision in his strokes. If the surface is moving at one place when you are hitting in another, you have to work several rounds to get it right. The reasons for this can be one of two: 1 - You are hitting too hard - try hitting looser and adjust the strength in your strokes according to how the surface is reacting. 2 - The surface is too thin or too much worked on - nothing you can do. You have to accept it or (at worst) start working on a new drum.
Fig. 6.4 Shaping an outer note. Note the line defining the working area.
The actual levelling is done in the same way as the shaping, but now more emphasis is put on the relative position of the notes. If the shaping is well done, the final levelling is just a minor adjustment.
Start the levelling on an outer note and work your way down to the corresponding inner note while checking that the top of each note dent is level with adjacent notes. Work around the pan octave-pair wise, adjusting the notes in the same octave to be level with each other see circles in fig. 6.5.
Fig. 6.5 Levelling result. Cross-section and overview.
This is also your last chance to mould the overall shape of the pan. Hereafter the surface will be fairly fixed. Hit the surface between the notes softly with the backing hammer. Try to get the surface level everywhere, making an even elliptical curve, except for where the notes are, see fig. 6.5.
The result of the final levelling is very important, because the border of each note has to have a certain curvature in order to get the right geometry to produce overtones that can be tuned to harmonics. See the theory section for more about overtones.
The last thing to do before cutting and burning the pan is to smooth it again, if necessary. Work all over the surface between the notes, hitting it softly with the smoothing hammer, examining the surface all the time, see fig. 6.6. The importance of smoothness of the surface at this stage can not be emphasized enough. The smoother the surface, the easier the pan will be to tune and the better it will sound.
Fig. 6.6 Final smoothing with plastic-headed hammer.