Why do I always find differences between composers when they write for the drum set?

For a long time drum set notation has been subject to the needs (or preferences) of composers. This is why we rely on the initial "legend" to explain the correspondence to the various instruments. Nevertheless, with the passage of time the benchmarks accepted by the majority of drummers are becoming more and more established. Which is to say: Bass drum in the first space, Floor tom in the second, Snare drum in the third, Small tom in the fourth and Hi Hat with sticks, with the classic “little cross” above the pentagram. For all the other instruments such as, for example, the second bass, different lines or symbols are used. So, even if the number of instruments to indicate have increased compared to the past, today one can already talk of the existence of a single notation for the drum set as well.

How come I'm not able to obtains a full-bodied roll from the snare drum?

To obtain a “full-bodied” or substantial roll on the snare drum, you have to adopt the technique of triple or multiple strokes (in place of the traditional technique of double strokes) because with these rolls you obtain more strokes with less movement of the hands. The double stroke roll requires a great acceleration of movements to produce many strokes, something that often translates into unpleasant and unexpected accentuation. On the other hand, by generating more strokes with less movement, you can achieve a roll that is more full with greater calm.

What are the principal rolls and how do they differ from each other?

The rolls most used for membrane instruments played with sticks are:
the single stroke roll, that is obtained by playing a single stroke with each hand, the double stroke roll, that is executed by alternating two strokes with each hand, the triple stroke roll, which is obtained with a triple stroke with each hand and the multiple stroke roll (which should not be confused with the so-called “dragged roll”) which is obtained, in theory, by executing an unspecified series of strokes with each hand, while, in practice, there are three, at the most four, strokes per hand. The difference lies, beyond the number of strokes in each movement, in the acoustic result, which can vary depending on the instrument on which the roll is being executed. With long resonance instruments, such as the timpani, for example, the single-stroke technique is preferred for its greater power. With short resonance instruments, like the snare drum, you use double, triple or, even better, multiple strokes to have greater continuity of sound with less movement of the hands.

What is the most appropriate technical gesture for playing in the proper way?

Playing correctly means that you make the characteristics that distinguish sound from noise easily identifiable, which is to say, pitch, intensity and tone.
In other words, the listener must never confuse the sound of the percussions with noise, even if you are playing instruments of indeterminate sound.
If I have to play only a single stroke on a snare drum, I can do it in two ways: leave the stick free after percussion, without obstructing the rebound, or accompanying the stick, both as it falls and rises.
In the first case, the arm has only accompanied the stick, while in the second, it was the arm that imposed movement on the stick.
The difference between the two striking modes, as regards the resulting sound and the muscular implications, is significant.
Leaving the stick free, you produce a sound that consists of a quantity of concomitant phenomena, among which are the vibration of the sticks, the instrument and nearby bodies in sympathy.
All these details enrich the sound, making it more complete.
On the other hand, if the stick is forced to follow the movement of the arm (in addition to an unnatural impact with a consequent danger of injury) you also have a loss of sound due to the attenuation of the principal vibratory phenomena and a total lack of the secondary ones.

Can the study of the “rudiments” be made more complete and learning time be shortened?

To make the study of the fundamentals more complete, shortening learning time, you have to change the method of study. Personally, I use technical syntheses based on all-inclusive readings. It has to do with a few exercises, of only one page each, with which you study technique, rhythm and reading all at the same time.
A good part of these exercised have been put into the video, “La scuola di percussioni e batteria” and can be studied with an entertaining karaoke. Which means that you can follow the notation on the video (while you're playing) because the coloring of the notes is perfectly synchronized with the music.

How come the roll with the attack of both sticks simultaneously is not used more often in musical practice, even though it is so useful and important?

The technique of a roll started with two sticks simultaneously arose from the need to standardize the attack of the percussions with that of all the other instruments in the orchestra. If the winds and the strings execute the held notes with a single attack, the percussions cannot adapt if they execute a double attack (in practice, the famous acciaccatura effect produced by a roll begun with a single stick).
It is obvious that the attack with two sticks simultaneously, both with the snare drum and the timpani, being an evolved form of the most known and widespread technique, is little used because it is more difficult to put into practice.
When orchestra directors and listeners become aware that the attack of the percussions can also be standardized with the other instruments, everyone will be forced to learn to execute an attack with two sticks simultaneously.

When and why should you damp vibrations on the timpani?

The vibrations must be stopped when it is necessary to give the notes their proper value. In other words, a stroke with the value of a fourth should be damped or else it would become a longer value and could interfere with the harmonies of the other instruments. However, it should be clarified that there are cases in which the resonance enriches the sound and doesn't disturb it. In these situations, there are no fixed rules and only the one playing can decide it is better to damp the vibrations or not. Naturally, to stop the resonance in a “piano” it's enough just to brush the skin, while in a “forte” a more decisive movement will be necessary.

Why do you hear halos or glissandos after a fortissimo?

When there is a great resonance, and you stop the vibrations with only three fingers, it can happen that you're not pressing a sufficient area with adequate force. If, then, you use a vertical grip, where you constantly have to turn the wrist to stop the resonance, you have to be even more expert not to leave an undesirable halo.

What can be done to facilitate dampening and eliminating all the undesirable vibrations?

If you want to stop the vibrations more easily, it helps to use the grip with the palm turned towards the floor, or at least an intermediate grip.
With this grip, it's enough just to open the fingers to already be in position.
To eliminate undesired halos or glissandos, it's a good idea to stop the skins with the thumb in such a way as to press a larger surface area with greater force. Moreover, by freeing the thumb, it is possible to stop two timpani simultaneously with only one hand

Is it true that speed in the strokes of a roll can damage the quality of the sound?

It's not only the speed of the movements, but also the way in which you “drive” the strokes. To achieve a continuous sound, especially when using very hard sticks, it would be necessary to give the skin time to vibrate, exploiting its natural rebound. If the strokes follow one another too quickly (and violently), they dampen the vibrations of the preceding strokes and generate a terrible sound. The result, in this case, would be hammering without vibrational continuity.

If you begin studying on a xylophone, will you have problems moving to the vibraphone and marimba because of the different distances?

It is more than a question of distances because the instrument you start on determines the training and development of your musical ear. Which is to say, the fundamental requirements for successfully beginning the study of music.
Wood instruments have short sounds and have difficulty preserving their tuning. For these reasons, it is much better to begin the study of the keyboard with the vibraphone that, in addition to having long, velvet sounds, maintains its tuning better than a piano.

In an old drums method, I saw gymnastic exercises for loosing up the limbs. Why were these exercises abandoned and not used any more today?

It happens that useful things are abandoned in every field, while the things that need to be updated are still being used. Preparatory gymnastics were much in vogue towards the Forties, especially for the snare drum and drum set. The exercises to do were very simple and effective and were intended, more than anything, to facilitate the twisting of the wrists and the movement of rotating the wrist and forearm of the left hand, which had a different grip.
Today, preparatory gymnastics, in addition to the drum set, could also be useful for loosening the wrists of keyboard players who have to adapt to complicated twisting motions, and to strengthen the finger that must support the weight of two mallets.
The exercises to do (for those who use the position with mallets independent) were already proposed and tested with the method, “La marimba” (Milan 1998) and serve to achieve a more stable grip and greater force and independence in the fingers and to facilitate the movement of opening and closing the mallets.

What is the four-mallet grip most suitable for playing both the marimba and the vibraphone?

All the grips can work well for playing both the marimba and the vibraphone, depending on what it is you have to play. Often a grip that has proven itself to be excellent in the wide spaces, is not equally as advantageous in the narrow ones. In fact, in addition to the marimba and vibraphone, it also happens that you play four mallet pieces on the xylophone and even the glockenspiel.
The most reasonable thing to do is learn to make the small adjustments to your own basic grip, as happens in various different sports. In this way, you can play all the direct percussion keyboards and almost any musical genre, always using the same basic grip.

Many keyboard players, to be sure not to mistake the notes, learn the piece to be played by heart, is this right or wrong?

The habit of studying “by heart,” especially in the initial phase of study is, unfortunately, very widespread. This system is certainly not advisable for instruments like the marimba, xylophone and vibraphone. In the first place, because you can't always practice (think of recording sessions or in the orchestra when the parts are brought at the last minute by the conductors themselves). In the second place, because the classic “memory blank” can happen to anyone, and at any moment, with dramatic results for the performer.
On the other hand, the study and execution of memorized pieces at a concert level is a whole other story and, no doubt, a reason for pride; inasmuch as it is true that, if a graduating pianists program is performed from memory, they earn some extra points in the final grade.
In conclusion, we can state that memorizing can be, depending on the case, either right or wrong. This because a beginner must first of all learn to perform the piece by reading it; while the soloist, who has reached his full technical maturity, can allow himself “the luxury” of deciding from time to which system to favor. Many times, you choose to perform “by heart” also to be free to concentrate exclusively on the interpretation.