Mental training involves structured cognitive exercises aimed at reinforcing focus, reducing stress, and optimizing performance. Sisterhen (2005) examined the effectiveness of different mental practice techniques among five participants over a four-week period. The study found that mental practice positively influenced final performance, self-confidence, anxiety management, memory, and concentration. However, shorter sessions (approximately 5 minutes) proved to be the most effective in maintaining focus and motivation.

One of the most beneficial techniques reported was hearing the piece while reading the score, allowing musicians to mentally "listen" to the music while following the notation. This technique improved structural awareness and detail recognition. Another useful strategy was physically tapping the rhythm while reading the score, which reinforced rhythmic accuracy and focus. Additionally, visualizing the score in the mind enhanced the ability to anticipate and recall musical passages (Sisterhen 2005).

The pianist Jorge Bolet emphasized the importance of mental practice, stating that he often solved mechanical and interpretative challenges in his mind rather than at the keyboard. Similarly, Liu Shih-kum, a pianist imprisoned for six years during the Cultural Revolution, maintained his performance abilities through mental practice alone, demonstrating the power of cognitive rehearsal in maintaining technical skills (cited in Sisterhen 2005).

Laroy Horace Borchert’s study (cited in Sisterhen 2005) explored mental imagery in musical performance by comparing different instructional approaches. One group received verbal instructions, another used imagery-based guidance, and a control group relied on physical practice alone. The imagery group demonstrated the most improvement, particularly in accuracy and articulation. These findings suggest that structured mental imagery can be as effective as physical practice in certain aspects of learning and performance.

Mental training techniques are also supported by experts such as Francisco Cantó, clarinet professor at the Conservatoire of Seville, who integrates meditation into his preparation. He dedicates 15-20 minutes to clearing his mind through breath control before practicing, which enhances focus and emotional regulation. He also highlights the importance of thought in physical readiness, using techniques such as smiling to relax the throat and imagining yawning to maintain jaw flexibility.

"Our instrument is just a tool – an amplification of what’s inside us. The true music takes place in our mind."

 Forrest (2019)

Imagery techniques help musicians refine their interpretation, improve confidence, and develop a deeper connection with their instrument. Malva Susanne Freymuth (1999) proposed a three-step practice loop: ideal projection, action, and mental recall. Musicians first imagine the ideal sound they wish to produce, then attempt to recreate it physically, and finally recall the result to compare with their initial mental projection (cited in Sisterhen 2005).

Susan Bruckner (1998) emphasized three visual perspectives in imagery training (cited in Sisterhen 2005):

First position: The musician imagines themselves performing, engaging visual, aural, and kinesthetic senses.

Second position: The musician mentally steps into the audience’s perspective to evaluate their performance.

Third position: The musician envisions the performance from a distant viewpoint, fostering a sense of neutrality and objectivity.

More interviews were conducted for the 'mental' part of the warm-up, and here are some insights from various experts:

Wieke Karsten mentions a similar three-step approach, what she calls the "musician's law":

- Feeling the pulse of the music in the body.

-Hearing the sound mentally before playing.

-Finally, playing with complete connection. 

Irma Kort uses mental imagery to release tension. She suggests visualizing the head as a “helium balloon” to alleviate neck and shoulder stiffness. Another effective approach is imagining the body expanding in different directions to improve posture and breath control.

Jan van Beek suggests incorporating mindfulness and emotional awareness into musical training. His techniques include:

• Identifying emotions through a body scan.

• Using visualization in Acceptance and Commitment Therapy (ACT), where emotions are assigned a color, shape, or location in the body.

• Practicing “Box Breathing” (inhaling, holding, exhaling, and pausing for equal counts) to regulate stress.

Susan Williams proposes visualization techniques by mentally rehearsing performances the night before, imagining every detail from stage setting to sound production. She also stresses the importance of positive intentions, as self-beliefs—whether encouraging or discouraging—affect real performance outcomes.

Similarly, Laura Ortiz highlights the neuroscientific basis of mental practice, explaining that the brain processes imagined performances as if they were physically executed. Studies with pianists have demonstrated that those who solely visualized playing a piece achieved similar learning outcomes to those who physically practiced it. She also advocates for “square breathing” (inhaling, holding, exhaling, and pausing for four counts) to calm performance nerves.

Annelien Van Wauwe believes in integrating yoga into her mental and physical preparation. She mentally structures her practice sessions in advance and uses motivational techniques to sustain engagement. She emphasizes accepting emotions without judgment and building confidence with simple mantras like “You are well prepared” or “Go with the flow.”

1. Short mental practice sessions (5 minutes max)

• Hear the piece while reading the score.

• Tap the rhythm while following the notation.

• Visualize the score mentally.

2. Three-step imagery-based warm-up

• Feel the pulse in the body.

• Hear the sound internally before playing.

• Perform with full connection.

3. Visualization techniques

• First position: Imagine yourself performing.

• Second position: Observe yourself from the audience’s view.

• Third position: View from afar for objectivity.

4. Breath control for stress management 

• Box breathing (inhale-hold-exhale-hold for equal counts).

• Square breathing (inhale-hold-exhale-hold for 4 seconds each).

5. Emotional mindfulness and visualization 

• Identify emotions with a body scan.

• Assign colors or shapes to emotions for better awareness.

6. Meditation and focus techniques 

• Meditate for 5 minutes before practice to clear the mind.

• Use positive thoughts (smiling, imagining yawning) to prepare the body.