Practicing a piece of music without the instrument to guide you is an exercise in the depth and wholeness of your understanding of a piece outside of your physical capacity to repeat motor simulation - muscle memory. Understanding a piece that you are playing, and that means making it all make sense to you is a fundamental step of memorization, after all if we do not truly understand what we are playing we are much more likely to get lost and not know where we are at all, much like waking up from a hypnosis trance and not realizing that you were in a theatre all along!
In stage of during a lesson, or even for our own enjoyment and standards of personal practice we cannot afford the seconds of complete inertia that come from waking from a dreamlike state, nor the panic that accompanies not knowing where you are. So, your best ally is to explore the depths of your understanding so that when the opportunity of forgetfulness arrives in say a Bach fugue, your brain will simply complete the picture - ‘we have just finished the first subject, so we therefore must start the next passage on a G!’
Begone blank minds! Interestingly enough, working away from the instrument is not only a way to practice this kind of integral memory, but it is the best way to do so. This is because you are not being distracted (or prompted) by the presence of the instrument - which is your tool not your enemy when it comes to memory - which means you are exerting full capacity to concentrate on the mental process behind what the fingers perform. It also gives you more chance of avoiding injury in your practice because your physical movements will always be more conscious once you have done the slow thinking work behind the reflex decisions your body makes whilst playing.
A word of caution!
Work from a level of understanding that you understand.
Doesn’t that sound simple! Let’s unravel a little what that means. Understanding something is a complete process and when it comes to working with a musical score partial understanding is going to leave you feeling that you do not understand eventually. That doesn’t mean that you must understand the complete harmonic/melodic story of a work or be able to do a schenkerian analysis of each passage you play, but it does mean that you should find a way that you can make each thing you are working on make sense to you with the tools you already have available to you.
Perhaps you have just started a basic harmony class and are playing a passage from the classical period. Find the key of your piece, the tonic chords and the dominant chords and hang the rest of the notes on the certainty of those bits of knowledge that you can understand. It is far better to localize a dominant chord and hang 9 different pitches around that chord that you understand and that means something to you than to find an analysis of the whole passage at length with each harmonic inflection and try to memorize each one. This simply won’t mean anything to you, and it won’t be something that helps when it comes to recall or to developing an interpretation. You must start with your own basics and color those in in a way that you completely understand.
So, with that in mind here are 5 ideas for practicing without the instrument:
1. Structural Analysis
When it comes to interpreting the temporality of a piece of music, little will be more useful to you than making sense of the structure of a piece. This can be done in a number of ways, but useful will be first to identify what the ‘core’ melody, chords or theme of your piece is and to briefly describe or decide what journey this element takes. You may find that there are two ‘bookend’ themes with an elusive middle sandwiched in between, perhaps the first theme only comes back in a mutated manner, perhaps the whole piece appears to be a big jumble. Find peace in this chaos and make a story in your mind of what this element appears to undergo. Try not to attribute terminology unless it truly means something to you, after all, if you say ‘this piece is in sonata form’ but only a vague memory of writing a question answer to this in high school springs to mind then this probably won’t leave you feeling any wiser. Remember the point is to make sense of and understand with the tools YOU have available to you, not defend yourself against a music historian.
Do not worry if your analysis does not completely tie up, or if you do not find a theme where you thought you might, this is not cracking a code, make sure you remark the passages that are written differently than you otherwise would have thought and remember that marking the extraordinary is much more useful on the pathway of knowledge than of trying to document patterns that run similarly.
2. Harmonic Patterns
At whatever level you are, working out a few of the harmonic figures in a piece of music will help you in your quest for memory and awareness during your playing. You do not need a complete harmonic understanding to make a decent analysis of a piece, but something that is useful is to mark throughout your music will be harmonic figures that symbolize ‘home’, ‘movement’ and ‘unrest’, or in harmonic terminology, the tonic (home key), dominant and subdominant figures and ‘anything else’! Understanding which notes make up the home key and its counterpart chords will help greatly in your understanding of the story a piece is telling harmonically, and it will help it make sense to you during your playing.
3. Right Hand Figures
Right hand technique in general is something that is greatly overlooked in the guitar world, and yet it is one of the building blocks of learning, from the basics right up until professional level playing. Perhaps because the left hand looks so tricky, we often ignore the difficulty in the right hand unless we are playing a specific virtuosic right-hand technique or a passage that is incredibly difficult. However, learning to memorize your right-hand fingering will help massively when it comes to your memory practice, and for precision during passages that are complex for the left-hand.
In order to do this without the instrument it is important that you start to develop a sense of the mind-muscle connection with the right-hand fingers, this will also massively benefit your right-hand playing level. With your eyes closed lie your right hand on your leg or a table and face the palm skywards. From this position slowly and mindfully extend first your index finger upwards completely isolating the movement from that of the other fingers. No other finger should move at this point. Release the finger back into the relaxed lying position and then start with the middle finger. Complete the process for all fingers and repeat as necessary until you feel that on demand you could move one finger and leave all of the others lying limp.
Once your practice of this exercise starts to feel basic you can move to performing simple right-hand passages from pieces you are playing, you can do this without moving the fingers visualizing alone the movement that the fingers will make on the instrument. Be sure that you are visualizing not just which finger but also which string each finger will make contact with.
4. Note names
A classic, but not any less effective. Either with note names or in solfege, run through your piece naming each note (this work is particularly effective if you have practiced saying or visualizing note names whilst playing the notes on the instrument). During the first stages of this kind of practice it might be useful to look at the score and to read the names mono-rhythmically. As you become more used to this style of reading and internalizing you can begin to name the notes in rhythm and then even away from the music, adding in for instance the right hand playing on your leg in place of the instrument.
5. Score Visualization
For those who have photographic memories this will sound obvious but visualizing the score in the mind's eye can be incredibly useful for recall at a later date and there is no better time for this than when studying the score in isolation. Try to really pour over each passage slowly and practice recalling the shapes and patterns of each phrase, or each couple of notes many times in a row, you can then consolidate this memory by writing each phrase out like lines of dictation. A word of caution here that writing something out will only benefit you if you know that you know it. Guessing and miraculously getting it right will not help you here!