The electronic musician Tor Bruce (personal communication, February 10, 2013) offers an excellent set of criteria for a beginner-oriented music application:
If someone who doesn’t know the first thing about music, and never used the software before, sits down and tries it out for a couple of minutes, will they be able to make something that sounds like music? Or will the output just be random sounds, without even the most basic harmony or rhythm in place? Is this an app for making music, or just an app for making sounds (from which you can make music, if you already know how music is made)?
When studying an instrument, it can be weeks, months or even years before it is possible to produce a satisfyingly musical sound. Software is easier than acoustic instruments, but beginners can still be easily discouraged by the difficulty of producing something that sounds good. The Drum Loop imposes some limitations on the user that are designed to make it impossible to produce totally unmusical sounds. By giving the user “freedom from choice,” users are not overwhelmed with a rush of new concepts.
There is a widespread tendency in musical interface designers toward skeuomorphism, the practice of retaining ornaments and metaphors from older technology that were necessary in the original, but are unnecessary in simulation. Graphical representations of “realistic” hardware like mixers, rack-mounted effects processors, amplifiers and so on are ubiquitous in music software. These visual cues are informative and helpful if the user is familiar with the original equipment. However, for a great many users, the software is their first experience of any kind of music production tool. They must learn hardware interfaces by clumsily manipulating onscreen graphics.
The Drum Loop eschews skeuomorphism. Its visual vocabulary consists entirely of flat-colored geometric shapes and text. The graphics refer to no other experience except the Drum Loop itself. In addition to the lack of distracting or misleading visual metaphors, the flat design has the added virtue of being attractive in its own right, drawing the user in.
Enforcing 4/4 time
Nearly all electronic dance music is in 4/4 time. Very occasionally, one may encounter triple meter or more complex time signatures. The Drum Loop could easily be programmed to support any arbitrary time signature simply by changing the number of wedges. But it was decided that the user should be limited to time signatures that are idiomatic to dance music. The Max prototype allowed the user to select between loops of eight, twelve, sixteen or thirty-two steps in length. However, for the sake of simplicity, the iOS app is limited to eight or sixteen step patterns only. Perhaps a future version will offer “advanced mode” in which the user can select any number of steps.
Common time and cut time
Even when we are confined to 4/4, the tactus (the perceived underlying pulse) is a matter of some confusion. Martens (2011) demonstrates how tactus choices are ambiguous between individuals and within musical excerpts, demonstrating that they do not have a straightforward basis in tempo. Untrained listeners search for the tactus in surface features of the music, but if they do not detect a consistent pulse there, they will seek it at the next metrical level up. A single individual can hear the same piece of music as possessing a different tactus on different listenings.
Given the inherent ambiguity in the definition of a beat, labeling the steps in a time-unit box system poses a challenge. Should each step be an eighth note? A sixteenth note? A thirty-second note? Common 4/4 time uses a sixteenth-note pulse, placing snare backbeats on beats two and four. However, many musicians dislike having to read sixteenth notes, and prefer to use cut time. The pulse is counted twice as fast, so the snare backbeat is the third beat of each measure. In my experience, formally trained musicians tend to prefer common time, while informally trained musicians (like myself) tend to prefer cut time. For beginners, the distinction between the two is a major source of confusion.
The Roland TR-808 drum machine evades the common versus cut time issue by simply labeling the steps in the drum pattern one through sixteen. Users can choose to interpret those numbers how they see fit. One must simply learn that snare hits go on steps five and thirteen. The steps are grouped by color into sets of four, which helps visualize the metrical scheme, but it is far from a user-friendly system. Most software drum machine interfaces use a variation on the TR-808 paradigm.
The Drum Loop allows the user to choose between common time (each wedge is a sixteenth note) and cut time (each wedge is an eighth note.) The grid looks the same either way; only the labeling of the wedges changes. Rather than having to count steps, users can use visual cues to conceptualize the metrical scheme. Snare backbeats fall on right and left, or three o’clock and nine o’clock, or east and west, however you prefer to think. Beginners do not need to worry about the nomenclature; they can focus on the broader concept of time being subdivided equally. Users may toggle the common/cut time switch out of curiosity, which presents an opportunity for self-directed learning.
Sounds and drum kits
The number of sounds in each Drum Loop kit is limited by the spatial constraints of the user interface. It is practical to include at most eight sounds in a given kit; otherwise the grid rings become too narrow to be easily read and written to.
All kits have the same four basic sounds: kick, snare, and closed and open hi-hat. Many dance beats require no sounds beyond these four. Each kit also has four more ornamental sounds: clap, rim shot, ride cymbal, bells, congas, tambourine and so on. Due to onscreen space limitations, the Max prototype was only able to accommodate six sounds per kit, a significant limitation of the ring spacing scheme (see below.) In theory, using the current layout, any number of sounds could be included, but eight represents a reasonable compromise between variety and simplicity.
The initial three drum kits were acoustic, hip-hop and techno. All three were sampled from Ableton Live for expediency. The acoustic kit uses one of Ableton’s rock drum kits; the hip-hop kit consists of Roland TR-808 samples; and the techno kit uses Roland TR-909. (If I release the Drum Loop commercially, I will need to create my own samples.) The problem is that these three kits were insufficient for all of the patterns I wished to include, especially the Afro-Cuban ones. So several more specialized kits needed to be developed to accommodate the different needed combinations of percussion sounds. Specific patterns are associated with certain kits by default, although the user is welcome to change them.
I struggled to find a set of eight drum sounds that could accommodate the stylistic range of the lessons. One possible solution would have been to use different drum instruments in the three kits, giving a possible twenty-four different sounds total. Practically, though, fewer drum sounds were possible because all kits needed to have basic sounds in common. The problem was that if, say, the cowbells were included in the Acoustic kit and the congas in the Techno kit, there would be no way to use those sounds in the techno and acoustic timbres respectively.
The ultimate solution was to expand the list of drum kits to have six different kits comprised of a total fourteen drum and percussion instruments: kick drum, snare drum, closed hi-hat, open hi-hat, handclap, rim shot, tambourine, shaker, ride cymbal, crash cymbal, high conga, low conga, high cowbell and low cowbell. All kits include kick, snare, and closed and open hi-hat. Each kit has four additional more specialized sounds, as follows:
- Soul kit: clap, rim, tambourine, shaker
- Rock kit: clap, rim, ride, crash
- Conga kit: rim, ride, high conga, low conga
- Bell kit: rim, ride, high bell, low bell
The Hip-Hop and Techno kits use the same set of instruments as the Soul kit. However, rather than using the Soul kit’s acoustic samples, the Hip-Hop and Techno kits contain equivalent instruments sampled from drum machines.
A wider variety of sounds would present a wider variety of sonic choices. However, placing strict limits on the sounds available has its own creative advantage. It eliminates option paralysis and forces users to concentrate on creating interesting patterns rather than struggling to choose from a long list of sounds.
Tone, velocity and effects
IIn the current version, the Drum Loop does not offer any tone controls like duration, pitch, EQ and the like. This choice was due to a combination of expediency and the push to reduce option paralysis. However, velocity (loudness) control is a high-priority future feature. While nuanced velocity control is not necessary for the artificial aesthetic of electronic dance music, a basic loud/medium/soft toggle would make the Drum Loop a more useful production tool. For example, the “Ashley’s Roachclip” break has a tambourine hit on every sixteenth note. When these hits played at a uniform velocity throughout, the result is exceptionally awkward; the pattern only sounds musical when each alternate hit is softer. The planned user interface design for velocity is to default all drum hits to medium. Users can then swipe upwards or downwards on a filled cell to toggle the velocity to loud or soft respectively. Velocity will be indicated with greater color saturation for loud and less color saturation for soft.
Color and typography
The goal with the color scheme is to make user interface elements maximally distinguishable, while still using an economy of colors, re-using wherever possible. Initial versions of the design, including the Max/MSP prototype, used a white background. This choice makes sense on a desktop or laptop screen, but is less satisfying on an iPad. Many iOS music apps use dark or black backgrounds, including GarageBand, O-Generator, Loopseque and (to a lesser extent) Figure. The dark background forced the use of light-colored text, the brighter the better for legibility.
Nearly all text is Helvetica Bold, though text boxes and menu options are regular Helvetica for ease of legibility.
The menu structure is diagrammed below.
The main menu is the first screen visible when the app loads.
The other menus follow an identical graphical presentation; for example, here is the screen listing the Breakbeat exercises.