E,A,D,G tuning (from lowest to highest-pitched strings) as the double bass and bass guitar, 5-, 6, 7- and 8-string models are also available (though instruments other than four or five strings are uncommon). Like the double bass, most EUBs can be plucked ("pizzicato") or bowed. For an EUB to be bowed, it must have a curved bridge, so that the bow can be used on all of the individual strings. History The first production electric upright basses were developed independently in the mid-1930s by Regal, Vega and Rickenbacker. However, in the 1930s and 1940s, neither the transducers nor the amplification equipment then available could accurately reproduce the deep tones of the acoustic double bass. This may have contributed to the lack of public interest in either the electric upright basses or Paul Tutmarc's bass guitar-style instruments that emerged in the 1930s. In comparison with other electronically amplified string instruments, such as the electric violin, viola and cello, the EUB has been taken up by a wider range of players, perhaps because a traditional upright bass's size and weight makes it challenging to transport when compared to smaller instruments in the family. Description Scale length and tuning The scale length of EUBs varies: some scales are 42", similar to most double basses, whilst other models have scale lengths of only 30" like a short scale bass guitar. The shorter scale can make it easier for bass guitarists to convert to the EUB. Some scales lie between these two extremes, for example 34", like a long scale bass guitar. The fingerboard extends over two octaves and usually has side dots for the player's reference. Regardless of scale length, the strings are usually tuned to E1, A1, D2, G2 (see Scientific pitch notation) at the same pitch as the double bass or bass guitar. Aids in playing Double bass players use features of the instrument such as the neck heel and edge of the upper bout as tactile positional references. The rear of the body of an upright bass is usually braced against the hip with player standing or knee if sitting. Many EUBs therefore mirror these features in their design. There will often be a raised reference point about 1/3 down from the nut to the bridge at either the "D" or "Eb" position (where the notes "D" or "Eb" are found on the "G" string)) to represent the 'neck heel' of