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.
 

Listening Practice
The below tracks are listed in order of increasing number of instruments. The first is the simplest, comprising just the bass tumbao with the conga pattern as a reference; the bass tones are at their most obvious. The second has an additional clave rhythm, providing a second reference point to synchronise your dance rhythm to. The third adds the rich complexity of the piano to establish the context of a modern son track. The bass tones are still audible, you just have to understand where to listen for them. Listen to each in turn:

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

Spend enough time on each to make sure you can pick out the bass tones underringly. Outside of this tutorial, listen to the salsa songs that you have and pick out the bass lines in the rhythm section.

Note: compressed formats like mp3 suffer compromise at the ends of the frequency spectrum. You may need to boost the bass tone on your sound playback system to help you pick out the bass more clearly. Gradually reduce the amount of boost as you become better at identifying the bass tones.
 

An Example Bass Rhythm
Using the first track, tap out the rhythm of the bass tumbao. You will find that it can be represented visually like this:
 

Figure 7.1. Tresillo bass rhythm
 

The rhythm consists of three-beats, called the tresillo, which is repeated in every bar. The tresillo is identical to the 3-side of the son clave:
 

Figure 7.2. Tresillo bass tumbao and son clave
 

In other words, we can achieve this fundamental bass rhythm simply by repeating the 3-side of the clave instead of alternating it with the 2-side. Verify this by listening to the second track. Then clap the tresillo in time with the bass tumbao.
 

Pulse And Tresillo
Establish the pulse rhythm by tapping it with your foot. Make use of the conga's tumbao moderno as a reference point if you have to, but it would be preferable if you could use the tresillo (i.e. clave 3-side, as covered in the Stage I tutorials) directly.
 

Figure 7.3. Tresillo bass tumbao, conga tumbao,
pulse and son clave
 

Once you have stabilised the pulse to tresillo, replace your foot taps with alternating steps to create a pulse walk. Then clap the tresillo in agreement with the bass tumbao as you walk the pulse (independent expression of rhythm). In this manner, it becomes obvious that the bass tumbao:

1. has a propulsive effect on the rhythm section because it creates a point of rhythmic tension in every bar of music;
2. in coinciding with the conga open tones, emphasises the beginning of the African rhythm cycle;
3. falling on the beginning of every bar, emphasises the beginning of the European rhythm cycle.
    

Step Rhythm And Tresillo
Convert the pulse rhythm to the salsa step rhythm (referring to Stage I tutorials as necessary):
 

Figure 7.4. Clave, tresillo and step rhythm
 

Notice that the tresillo-based tumbao both complements and agrees with the step rhythm:

• the first beat of the tresillo coincides with the beginning of the step rhythm (agreement); and
• the last beat of the tresillo reinforces the open-tone cue of the conga, which occur in alternation with the beats of the step rhythm (complement).

Practice synchronising your internal metronome and dancing the step rhythm using the bass tumbao as your sole reference point. Do so with each of the three tracks provided.
 

A Classic Tumbao
A way of playing bass is to adopt a minimalist approach, whose ideal is 'to lay down the best possible groove using the fewest possible notes'. It creates an open rhythm structure with the most room in which the ensemble players may express themselves.

In keeping with this approach, a classic tumbao played in son takes the tresillo pattern and omits the first note in every bar creating a bass rhythm that emphasises the bombó and the ponché:
 

Figure 7.5. Son clave, bass tumbao and step rhythm
 

Using the three tracks (containing the tresillo bass tumbao) provided:

1. Dance the step rhythm and clap you hands only on the bombó and ponché.
2. Dance the step rhythm and mentally voice the bass notes played on the bombó and ponché. It doesn't matter if they are the right notes, we only need to be sure of their rhythmic location.
3. Ensure that you can voice these notes to clave: a 'clave only' or 'clave and tumbao moderno' track can be downloaded via the Index of Tracks.

These practices will solidify your feeling for the rhythmic location of the bass notes; you will know where to expect them in a song. Proceed to applying your knowledge in context by dancing to sones, and identifying the songs that are driven by this bass tumbao. I recommend songs by Trio Matamoros, Ignacio Piñiero, Sexteto Habanero, and Sierra Maestra as good places to start.

The classic bombó-and-ponché bass tumbao should not be considered rigidly as the "be-all and end-all" of bass rhythms. Indeed the bass is played much more fluidly than that, and many variations abound as you'll soon discover. Instead think of this rhythm as a skeletal structure set up by the bassist, who will embellish it occassionally as he or she feels fit.

Some of these bass adornments can even indicate clave direction...
 

Gleaning Clave Orientation
There are no 'hard and fast' rules for indicating clave orientation on the bass; the bajista [bass player] might choose to do so in order to reinforce the clave feel, or he might just be messing with you. Here are some motifs I might use:
 

Leaning on the 2-side
A variation of the classic tumbao where one more note is played on the first clave beat of the 2-side:
 

Figure 7.6. Classic bass tumbao plus the first note of clave 2-side
 

Based on the clave property of non-superimposability, the listener should be able to determine clave orientation with this simple addition.
 

Leaning on the 3-side
Another variation of the classic tumbao with one additional note played on the first clave beat of the 3-side:
 

Figure 7.7. Classic bass tumbao plus the first note of clave 3-side
 

Again, the non-superimposability of the clave should tell the listener that the alternating appearance of the tresillo literally expresses the 3-side.
 

Literal interpretation of the conga's tumbao moderno
In a previous tutorial (Conga: indicating clave orientation), we saw how a conguero [conga player] could choose to indicate clave orientation by alternating between double-open and single-open tones on the clave 2-side and 3-side respectively. The bassist can choose to do the same, even if the tumbao moderno is not being played.
 

Figure 7.8. Literal interpretation of the tumbao moderno indicating clave orientation on a single conga
 

And Finally
The most enduring approach to learning how to synchronise your timing to the bass tumbao is to avoid being prescriptive. Knowing what forms the tumbao could possibly take, to the extent of understanding the rhythmic strategies behind them, is your best route to success. What we have covered thus far will stand you in good stead as a rhythmic dancer. But if you want more, turn the page.