What are double bass extensions and how do they work? - Double Bass HQ

For centuries, composers and performers have experimented with various tunings and numbers of strings on double basses.

While the standard double bass tuning is EADG (low to high), most music in the orchestral canon is written down to a low C.

This means that players using a standard four string double bass aren’t actually able to play all the notes that composers like Bach, Strauss, and Stravinsky wrote.

As a result, bassists have experimented with a variety of ways to reach those low notes on their instruments. This article takes a look at the various methods commonly used to play low notes on the double bass.

Part 1 – Evolution of the Double Bass Extension

I – Stenholm Machine Extension

The mechanical extension came on the scene in the 1880s, around the same time as the modern five string double bass was developed. The Stenholm machine extension is the most common example of the mechanical extension. This device consists of a series of levers next to the fingerboard which remotely activate metal keys on the extension fingerboard.

By 1940, Stenholm extensions had begun to spread in popularity, and they began appearing in the Cleveland Orchestra and Philadelphia Orchestra bass sections during the 1950s and 1960s.

By the time Orin O’Brien joined the New York Philharmonic bass section in 1966, four of the bassists had extensions. When any orchestral passages dipped below the low E, those players that had extensions played the low notes.

Extensions continued to gain popularity through the 1960s and 1970s, eventually becoming a standard piece of gear for professional orchestral bassists. Currently, the majority of orchestral bassists worldwide perform either on a five-string bass with a low B string or on a four-string bass with a C extension.

Advantages

Mechanically, operating a Stenholm extension is like playing a bassoon or bass clarinet. Each lever depresses a key for a specific pitch. This allows the player to play low notes without reaching above their head. With practice, this can be a very efficient way of playing low notes on the bass.

Disadvantages

While these extensions allow players to reach all the low notes of the bass, there are also several disadvantages. Metallic clicking sounds can result from these extensions if the player isn’t experienced using them. Also, like all mechanical devices, these extensions have a tendency to loosen and buzz over time.

Also, some string luthiers are reluctant to service these mechanical extensions, making repair a challenge.

The added bulk of this machinery adds a noticeable amount of weight to the scroll. This may make the bass feel unbalanced and top-heavy, adding to player strain, especially when standing.

II – “Stick” Extensions

Over time, luthiers and bassists began to experiment with different extension styles. One innovation was to completely remove the machine and use one hand-carved lever to open and close the extension. This means that the extension is either set on E or C, and the notes in between must be fingered with the left hand.

Often nicknamed the “stick” extension, this innovation reduced the weight on top of the scroll and eliminated the danger of buzzing.

Advantages

The major benefits of this style of extension are cost, weight, and maintenance.

Since this has the fewest moving parts, there’s less material and labor involved in installing this extension, which typically results in a lower cost. This also results in a lower weight than the Stenholm or the Chromatic extensions.

Since there are fewer moving parts, there’s less to maintain on the extension. While some adjustments to the E capo and other elements of the extension will be needed over the years, the reduced complexity tends to equate to less potential for maintenance.

Disadvantages

This type of extension makes playing anything other than E or C a challenge, however. Playing C#, D, or Eb requires the player to reach up above their head to close a note. While technically feasible, this quickly becomes tiresome when playing a passage with a lot of low notes.

Anyone who has had to play the seemingly endless low double bass Eb in the opening of Wagner’s Das Rheingold has longed for a better way to close those notes:

III – Chromatic Capo Extension

In the late 1980s, Don Robertson of Albuquerque, New Mexico’s Robertson and Sons Violins, invented the first fully chromatic capoed C extension. This style of extension features a closer for each note on the extension: E, Eb, D, and Db.

For many players, this extension combined the best of both worlds: a lighter and simpler mechanism with the ability to close each individual note.

These chromatic extensions opened up all sorts of resonance possibilities for the double bass. For example, setting the D closer is tremendously useful in many Bach passages that repeatedly drop down to the low D.

Also, setting the Eb capo can be useful in a jazz context, opening up new possibilities open up in a Bb blues when the player has a low Eb. The same applies to Db and C, depending on the piece being played.

The chromatic capo extension quickly spread in popularity, becoming the dominant form of double bass extension by the early 2000s.

Rob Anzellotti of Bass Capos continued to refine the closing mechanism used on extensions, and his capos are used in models by numerous luthiers worldwide. Luthiers also have begun making low B extensions, which add extra length to the double bass scroll but are a lot of fun in an orchestral context.

In 2018, Eastman Strings launched the first commercially available chromatic extension. Designed in collaboration with Lisa Gass of Los Angeles Bass Works, this extension is available on any Eastman bass. It features closers made of Delrin, a hard and lightweight plastic. It also allows for the adjusting of each capo to dial in the exact intonation for each note. This allows the bass to be exactly in tune on those low notes, even after a bridge adjustment or string change.

In addition to running this platform, I serve as Product Manager for Basses at Eastman. Here’s a video of me demoing this new extension:

Part 2 – Five String Basses Versus C Extensions

While C extensions on four-string basses are the most common set-up in the United States, most orchestral playing in Europe is done on five-string basses. There are several reasons for this discrepancy.

First of all, most European bassists use different instruments for orchestral playing and for solo/chamber playing. The orchestral basses are commonly owned by the orchestra and passed down from generation to generation of players. The player’s own instrument is frequently smaller, four stringed, and is frequently played in solo tuning (A E B F#).

Most Americans play their own personal double bass for orchestral playing, traditionally keeping it in standard orchestral tuning (G D A E). The addition of an extension allows American bassists to play the range required for orchestral repertoire while mainly using one instrument.

Many luthiers shy away from building five-string basses due to player preference, and there has been a tendency for many years to overbuild five-string basses to accommodate the added tension. While a well-built five-string bass will play well and sound great, five-string basses have a reputation for being difficult to play and sounding tight.

Outside of the United States and Europe, five-string and four-string basses with C extensions are common, and extensions are becoming more popular throughout Europe.

Passages where five-string basses shine

Some passages are simply too complex to play on an extension, and they can really only be cleanly executed on a five-string bass. This is a major advantage of a five-string bass. One great example of such a passage is letter D from the fourth movement of Beethoven’s Pastoral Symphony:

Passages of this complexity in the low register are rare, however, and bassists must balance the advantages of the five-string bass and the four-string bass with an extension.

Part 3 – Experiments in Tuning and Range

Bassists and bass luthiers are highly experimental, and they are constantly experimenting with new types of extensions and string arrangements. Many extensions add an extra half-step, taking the bass down to a low B. Low B extensions extend well beyond the scroll, and low B notes are rare in orchestral literature. Still, they are a lot of fun for both bassists, and they are seen on a small but substantial percentage of basses.

Some bassists have also begun putting extensions on five-string basses. Normally, the bassist adds a high C string as the fifth string with the traditional extension down to a low C. This effectively extends the range of the bass on both ends.

Some luthiers and bassists are experimenting even further. Los Angeles-based bass luthier Ralph Alcala recently put a double extension on a bass, extending the A string down to a low G and the E string down to a low C.

https://www.facebook.com/AlcalaStringLuthiery/posts/2374403169450010?__tn__=-R

This unusual extension opens up still more resonance and harmonic possibilities. Clearly, bassists and luthiers are in a golden age of low-note experimentation.

Part 4 – Notation Systems for Extensions

Players have developed various notation systems for showing how and when to open or close certain notes on an extension. The concept is similar to how a harpist marks pedaling in parts.

Unless these extension changes are clearly marked, players often scramble to make a quick change. Any bassist who has accidentally played a low Eb when they meant to play an E-natural knows the need for this notation system!

I – Stenholm and “Stick” Notation

On Stenholm extensions, bass players developed a simple shorthand for when to open or close the extension. The E closer locks into place on the nut when fully depressed on the Stenholm extension. Pushing on another key opens the extension, allowing all levers to be played.

There’s a noticeable mechanical “pop” when releasing the E key, so players developed a notational system to indicate when to open or close the Stenholm extension to avoid disrupting softer passages:

• xC = extension closed
• xO = extension open

This notation system applies to “stick” extensions as well since the only moving part is the E closer.

The following passage from the opening of Richard Strauss’ Ein Heldenleben illustrates how a player with a Stenholm extension would notate opening and closing the extension:

II – Chromatic Extension Notation

The development of the chromatic capo extension led to a more nuanced language for indicating when to open or close particular capos. For example, a particular passage may with a closed E, but the need for a D would occur soon thereafter.

In this case, players would write the note names to be closed in circles. Only these capos would be closed, with the others left open.

For unto us, a Child is born from Handel’s Messiah is a great example of this:

Toward the end of the movement, the player will open up the E capo to prepare for the low D notes at the end of the movement. Many players will notate this change during a rest as follows:

Part 5 – Extension Technique

With the rise in popularity of extensions came a need for new techniques for playing these extensions.

Many of these techniques are continuing to coalesce, and they are not taught in as consistent a fashion as more established techniques like thumb position and vibrato.

Still, they are an essential part of a modern bassist’s technical toolkit, and improper technique can lead to overuse injury, wrong notes, and general embarrassment.

Stenholm mechanical extensions have a technique all their own. Learning to navigate from clarinet-like metal keys to fingered string notes can be a bit of a learning curve, but most players find this technique relatively easy with practice.

Hand positions for capo and “stick” extensions

The chromatic capo extension introduces a whole new set of techniques, however. While there’s often a need for only one or two low notes in any given passage, other passages require the player to move their hand up to the scroll and actually finger particular passages.

This has led to new, somewhat unorthodox bass positions:

Zero position – 1st finger on the nut (E), 2nd finger on F, 4th finger on F#

Negative half position – 1st finger on Eb, 2nd finger on the nut (E), 4th finger on F

Negative first position – 1st finger on D, 2nd finger on Eb, 4th finger on the nut (E)

Negative 1 1/2 position – 1st finger on Db, 2nd finger on D, 4th finger on Eb

Since regular half-position is the maximum extension of a typical bassist’s hand, all of these new positions require the player to pivot the left hand slightly to reach these notes.

Also, the thumb needs to be placed on the scroll itself. Exactly where the thumb lands depends on the shape of the bass and the style of scroll and tuning mechanisms.

Though bassists can play on an extension in a standing position and while seated on a stool, most bassists find it challenging to execute extended passages on the extension while standing. Doing so requires the player to reach above their head to play these notes, shifting the balance of the bass rather dramatically.

Whether the bassist is standing or seated, it’s important to stay relaxed and keep the hand in as natural a position as possible when playing these low notes.

Chromatic capo extensions greatly help since passages will frequently only have one or two low notes. The chromatic extension can prevent a lot of wear and tear on a player by removing the need to keep the arm above the head for an extended period of time.