Acknowledgements
I would like to thank the salsa band 'Cuatro de Diciembre' (4de12) for their kind permission in providing me with excerpts and partial mix tracks for this tutorial. All music ©2005 written by Loo Yen Yeo and Jeremy Wise. All rights reserved.
 

Cáscara Rhythm

Listening Practice
The below tracks are listed in order of increasing challenge. The first is the simplest, comprising just the cáscara rhythm with the conga pattern as a reference so that the paila [timbale shell] tones are at their most obvious. The second has an additional clave rhythm, providing a second reference point to synchronise your dance rhythm. The third adds the rich complexity of the piano to establish the context of a modern son track. The fourth track has the clave rhythm removed, to validate your understanding of the cáscara's clave orientation.

Listen to each in turn:

• Cáscara and conga (3.6Mb)
  ©2005 Loo Yen Yeo and Jeremy Wise. All rights reserved.
• Cáscara, conga and son clave (3.6Mb)
  ©2005 Loo Yen Yeo and Jeremy Wise. All rights reserved.
• Cáscara, conga, piano and son clave (3.6Mb)
  ©2005 Loo Yen Yeo and Jeremy Wise. All rights reserved.
• Cáscara, conga and piano (3.6Mb)
  ©2005 Loo Yen Yeo and Jeremy Wise. All rights reserved.
   

Don't concern yourself with the rhythm at first. Just take the time to make sure you can pick out the shell tones confidently in all of the tracks. Listen to the salsa songs that you have and pick out the shell tones, which you would normally find in the first half of the song.

Now listen to the 'cáscara and conga' track, and tap your thigh or a tabletop with your fingers whenever you hear a beat on the shell. As you become accustomed to the rhythm, gradually turn down the volume of the speakers so that you can comfortably hear the drumming of your fingers as well as the shell. Keep on doing this to strengthen your sense of the cáscara.

You'll find it to be a repeated pattern one clave phrase long, which can be represented visually like this:
 

Figure 10.1. Cáscara, unrectified
 

Feature One: Couplets
The first thing I'd like for you to notice, is that there are four couplets, three of these occur consecutively, and one in isolation:
 

Figure 10.2. Couplets in the cáscara, unrectified
 

Continue with the listening and tapping exercise until you can confidently identify this motif.
 

Feature Two: Isolated Singles
Another important feature is that there are only two single notes, each preceded and followed by a couplet:
 

Figure 10.3. Single beats in the cáscara, unrectified
 

The singles act like interjections or hiccups, interrupting the stream of couplets. Understand this using the listening and tapping practice, and feel how your fingertips contact the surface. Match the feel and sound of your fingers with that of the cáscara; as if you were playing the rhythm on the track yourself.

Absorb the rhythm drummed by your fingertips in its entirety, being aware of these two key features. Listen to the cáscara and understand where these two features are. When you're comfortable and ready to move on, emphasise the second beat of the isolated couplet:
 

Figure 10.4. Accenting the start of the cáscara cycle
 

This is the actual beginning of the cycle (we will rectify the diagrams soon). Next tap your foot at the same time as you emphasise the beat:
 

Figure 10.5. Tapping your foot at the start of the cáscara
 

Now practice this exercise to the other tracks. If you like, you can try it with any salsa tracks you have lying around the house. This will help you become proficient in a real-world context. Don't be too concerned if what the timbalero [timbale player] plays doesn't always fit neatly in the box, these are just variations based on the same theme.
 

Rhythm Principles
The isolated couplet is a crucial feature in the way non-AfroCubans perceive the cáscara. If we overlay an European-standard count over the rhythm, we would have:
 

Figure 10.6. The cáscara rhythm expressed relative to a count
 

The first beat of the isolated couplet (beat 8+) is called a pick-up beat. That is it cues the beginning of the cycle in a manner similar to both the piano montuno, and the open tones of the tumbao moderno.

When we "rectify" the diagram to tutorial standard by moving the pick-up beat from the beginning of the diagram to the end, and add the son clave orientation, we get:
 

Figure 10.7. The cáscara rhythm with clave orientation, "rectified"
 

Notice that there are four points of agreement with the son clave, all but the ponché (the cáscara has full agreement with the rumba clave, see the rumba clave tutorial). As an advanced dancer, you might consider the cáscara a superset of the clave: if you can keep track of the rhythm and accent the clave stokes in your head, you can both phrase to clave and accenutate the upbeats for rhythmic 'ride' (see later). The only extra consideration is how you choose to handle the son ponché.
 

Dancing To Cáscara: Finding The Pulse
The cáscara is rich with upbeat accentuation and thus, although all but one of its beats agrees with the modern salsa step rhythm, the synchopations created by the couplets create a different kind of challenge to what we experienced with the montuno rhythm. We can simplify the process of synchronising to cáscara by finding the pulse first.

You will find that the rhythm does lend itself to effective time-keeping with respect to the modern salsa step rhythm because three of the four pulse steps are in agreement:
 

Figure 10.8. Cáscara with clave, conga and pulse
 

Step By Step

• Ignore the cáscara for the moment, and tune into the sound of the clave (and the conga if you must).
• Once you can make out the clave rhythm (or tumbao moderno), tap your foot to the pulse as per Tutorial Stage I.
• Gently let the sound of the cáscara slip into your perception. Let in as much paila as you can without sacrificing the stability of the pulse. Should you lose it at any point, regain the pulse rhythm by tuning into the clave (and conga) first, and then slowly let the cáscara in again.
• Be patient. You're developing your simultaneous perception of independent rhythms, and adding a very important rhythm to your dance vocabulary.
• Eventually tune out the clave and maintain the pulse relative to the cáscara. You would only need to tune into the intermediary rhythms every once in a while to check against rhythmic drift.
• To take your rhythmic independence to the next level (optional), tap out the cáscara rhythm with your fingers as you maintain the pulse with your foot. This is the simultaneous expression of independent rhythms.
• Move from tapping pulse to executing a pulse walk to cáscara.
• Convert the pulse walk to the full dance rhythm.

Figure 10.9. Cáscara with son clave, conga and step rhythm
 

The Devil's Ride
The cáscara is an examptle of a 'ride': a propulsive yet light rhythmic force. Like the montuno, the cáscara provides a current of beats which move the lyrics and melody forward.

Although it is a repeated pattern, the cáscara creates in the listener a sense of intermittency and unpredictability. These properties have caused music containing synchopated rhythms like the cáscara historically to be labelled as the work of the devil; and those who danced to them, beyond absolution.
 

Timbale Bell Rhythm

Listening Practice
The cáscara has a relative which prefers to make its appearance during the latter section of a song with the bongó bell. It takes its name after the bell which it is voiced on, the timbale bell (also called the mambo bell and more recently the salsa bell) which has a sharper, more aggressive tone - perfect for the higher energy-levels of the montuno section.

The tracks provided below follow the same strategy as those for the cáscara. Listen to each in turn:

• Timbale bell and conga (3.6Mb)
  ©2005 Loo Yen Yeo and Jeremy Wise. All rights reserved.
• Timbale bell, conga and son clave (3.6Mb)
  ©2005 Loo Yen Yeo and Jeremy Wise. All rights reserved.
• Timbale bell, conga, piano and son clave (3.6Mb)
  ©2005 Loo Yen Yeo and Jeremy Wise. All rights reserved.
• Timbale bell, conga and piano (3.6Mb)
  ©2005 Loo Yen Yeo and Jeremy Wise. All rights reserved.
   

Rhythm Principles
Timbale bell rhythms are played with more variation and fluidity than the related cáscara, but the basic variations follow a simple strategy:

1. There is an interjection on the first beat of the 2-side clave like the cáscara has.
2. There is a "run course" starting on the second beat of the 2-side clave and ending on the first beat of the bar immediately following the ponché, where longer runs of three or four beats are generally played instead of couplets to give more drive. (This does not, however, preclude the playing of single or double beats)
    

Figure 10.10. Comparison of cáscara and timbale bell strategy
 

Notice that the timbale strategy is in keeping with the clave principle:

• the beginning three beats of the 2-side are in agreement with the salsa dance rhythm and hence create rhythmic stability;
• the beats in the middle of the run course (on the 3-side) would feel intermittent by nature, creating rhythmic tension through the sense of instability.

Figure 10.11. Cáscara rhythm and two timbale bell variations
 

In the examples above, the run course of timbale variations 1 and 2 have beat configurations of 4-4-3 and 3-4-4 respectively. You can unserstand from the beat placement, the timbalero's intention to stress or dissipate various rhythmic features. And let's not forget that these variations aside, the timbalero can still add interjections, for example: a four-beat run can be substituted by a single and a couplet with a gap in between.

It's necessary to appreciate this rhythmic plasticity because as a dancer, in means that you cannot rely absolutely on being able to derive timing on the 3-side. Instead, you'd need to rely on your internal metronome and calibrate it against drift every 2-side.