Fretless AND Multiscale? Why?

A fretless multiscale bass sounds redundant until you separate fret placement from scale length. Frets determine where a player must stop the string to produce specific pitches. Scale length determines the mechanical conditions under which the string vibrates. Removing the frets changes the first part, but it does nothing to eliminate the tension and response problems that come with a five-string bass.

The Famine five-string bass uses a 37–35-inch multiscale, with the low B at 37 inches and the highest string at 35. It has a fretless Pernambuco fingerboard, polyurethane resin position markers, and a 12–20-inch compound radius. The main reason for the multiscale was tension. I wanted to increase the tension and authority of the low B while keeping the higher strings more pliable.

Intonation is less restrictive on a fretless instrument because the player can place a finger anywhere along the string. There are no metal frets forcing the notes into predetermined positions. Scale length still controls how the strings feel and behave, though, and that was the problem I was trying to solve.

A standard low B is approximately 30.87 Hz. At room temperature, that frequency has an airborne wavelength of roughly 36 feet. That number gives some perspective on how low the note actually is, although it is easy to explain it incorrectly. A bass string does not need to be 36 feet long to produce that frequency. The standing wave traveling along the string and the sound wave traveling through the air are two different systems. On a string fixed at both ends, the fundamental standing-wave wavelength is twice the string’s speaking length.

For an ideal string, the relationship between frequency, speaking length, tension, and mass per unit length can be expressed as:

f = 1/(2L)√(T/μ)

In that equation, f is frequency, L is speaking length, T is tension, and μ is mass per unit length. If the pitch and string construction remain the same, tension increases with the square of the scale length. Lengthening the same string from 35 to 37 inches raises its tension by approximately 11.8 percent. Two inches does not sound like much until the actual mechanical relationship is considered.

That increase is immediately apparent under the hand. The low B feels more secure, its attack is stronger, and the note comes through the amplifier with considerably more authority. On this bass, the difference between 35 and 37 inches was massive. The low B did not merely feel a little tighter. It rumbled out of the amp in a way that made the entire instrument feel larger and more substantial.

Real bass strings are also more complicated than the ideal strings described by the basic equation. A wound bass string has a steel core, multiple windings, considerable mass, and finite bending stiffness. Because the string is not perfectly flexible, its partials do not fall at mathematically perfect multiples of the fundamental. This is called inharmonicity. Research on bass guitar strings has found that inharmonicity becomes more pronounced with wider cores and shorter speaking lengths.

I would not claim that adding two inches completely transforms the harmonic structure of a low B. Scale length is simply one of the legitimate mechanical variables available when balancing tension, mass, diameter, and stiffness. Increasing the length changes the conditions under which that note is produced rather than somehow allowing the string to contain more of the 36-foot sound wave traveling through the air.

This is a more accurate way to explain why very long bass strings can sound so strong. Greater length gives the designer another way to reach a low pitch without relying entirely on a heavier and stiffer string.

The Alexander Piano is an extreme example that I often reference. Its builder, Adrian Mann, began with a direct question: what would an extremely long bass string sound like if it did not rely on conventional heavy copper loading to lower its pitch? He built an experimental string between posts, found a safe tension, and tuned it to the lowest A on a piano. That experiment eventually led to the Alexander Piano, an instrument nearly 19 feet long with extraordinarily long bass strings.

A bass guitar is obviously working on a much smaller scale, and an additional two inches does not produce the same degree of change. The underlying lesson still applies. Physical length gives us another variable with which to manage the compromises involved in producing very low notes.

The reason I chose 37–35 rather than 37 inches across all five strings is that the higher strings did not need the same treatment. A straight 35-inch scale is already common on five-string basses. It made sense to preserve that familiar length on the treble side and extend only the side that needed help. Running every string at 37 inches would have increased tension on the upper strings as well, which would have worked against my intention to keep them pliable.

I also find the spread on many multiscale instruments excessive. I have played instruments where the fan was so aggressive that it seemed designed to advertise the fact that the instrument was multiscale. When a large scale spread is paired with a perpendicular fret around the twelfth position, the geometry near the nut can become extreme. Common first-position shapes then require the player to rotate the hand or change established technique simply to accommodate the instrument.

The perpendicular position on this bass is at the sixth position. Moving it closer to the nut reduces the severity of the angle in the lower positions, where the physical reach is already greater and familiar technique matters most. My objective with multiscale design is to produce a useful change in string behavior without forcing the player to relearn the instrument. The fan should be as large as necessary to achieve the intended result and no larger.

Oddly enough, the multiscale layout may have been more ergonomic on this fretless bass than it would have been on a comparable fretted instrument. I am generally skeptical when multiscale is presented primarily as an ergonomic feature. Its real value, as I see it, is tension control. An excessive fan can easily make an instrument less comfortable.

Fretless playing changes the situation because finger placement must be so precise. On a conventional fretless board, the fingers often need to line up almost perfectly parallel when playing chords or closely grouped notes. With the position lines at an angle, the fingers can follow a more natural stagger rather than stacking directly beside one another. Some shapes were initially more difficult in certain areas, and the instrument required a brief adjustment period. Once I became accustomed to it, many things felt unexpectedly natural. My hand settled underneath the angled positions instead of fighting them.

The polyurethane resin markers were placed exactly where the frets would have been. They are functional position references rather than decoration. The player sees the correct location for each pitch across the multiscale layout and then makes the same fine adjustments that are required on any fretless instrument. The fan changes the angle of those positions, but it does not make the underlying scale layout mysterious.

String choice belongs at the beginning of a multiscale design, not at the end. Before committing to scale lengths, it is worth confirming the exact gauges, construction, total length, winding length, taper placement, and diameter the instrument will require. Those details are part of the geometry, because the most elegant scale layout still depends on a string that can be obtained and fitted correctly.

For this 37–35-inch arrangement, I found the appropriate fretless set from Payson. It is a specialized option produced in an annual run rather than a normally stocked set, so ownership simply calls for planning ahead: estimate the preferred change interval and secure enough sets during the production window.

My advice for anyone designing a multiscale instrument is therefore simple: choose the exact strings first. Confirm the gauges, construction, taper locations, usable lengths, and dependable source before finalizing the scale geometry. That approach keeps string supply as an intentional design parameter and ensures the finished instrument remains straightforward to maintain.

The finished bass worked exactly as I intended. It was light, the upper strings remained comfortable, and the 37-inch low B had the strength I wanted. It is my favorite fretless bass that I have ever played, and I genuinely wish I could have kept it. I would not change the scale geometry, the perpendicular position, or the way the instrument felt. The only addition I might consider on another one would be a piezo system with a blend control, simply to add another useful voice.

I would not tell someone who enjoys a straight 35-inch fretless bass that they need a multiscale instrument. If the string tension and response already feel right, there is no problem to correct. Multiscale is a corrective tool that becomes useful when the desired string set creates an imbalance between the bass and treble sides. On this instrument, I wanted a stronger low B without making the upper strings unnecessarily tight. The 37–35-inch layout solved that specific problem, and the absence of frets never made scale length any less important.

I am genuinely excited to make more of this particular bass. The combination of the fretless board, the 37–35-inch multiscale, and the way the low B speaks still feels full of possibilities, and I want to keep exploring it.