I think that the art of the bass is very often about finding and using the space between other instruments. In Sikth’s case (that’s how I’m going to typeset it, for anyone who actually likes it as SikTh), this is the space between two idiosyncratic and technical guitarists, two eclectically versatile vocalists and a drummer with the work rate of a Sherpa.
James Leach is the man charged with this duty, armed with a plectrum, drop C# tuning (as well as a G#–G#–C#–F# tuning), a custom–made five string McIntyre bass and a Sei Jazz five string bass. His general approach throughout Sikth’s two albums (their EPs largely consist of album tracks) is what most bass guitarists would consider to be sustainable for a highly challenging passage, tying together complex rhythms and revolving time signatures within complex and unconventional harmonic structures. For lack of a better phrase, Leach holds it down when the other instruments are jerking around (in the best possible way). Skies of The Millennium Night and Such The Fool are two good examples of this, with the other instruments playing complicated and diverging lines. That said, there are many examples of the bass forming a unison line with one of the guitars for a bar, tightly ascending or descending through a complicated lick. Death Of A Dead Day opener Bland Street Bloom is a good example of a balance between these two approaches, as are Flogging The Horses and Sanguine Seas Of Bigotry. The latter flows into an extended unison line at 1.40 for 30 seconds, as does Pussyfoot at 0.35. This fluidity in approach, the sealing of a sonic deal in multiple languages, is a distinguishing quality of Leach.
He chooses moments to shine, his calling card perhaps being his use of slap and pop, in which he employs lots of muted notes to create a very percussive effect. Summer Rain from 0.02 to 0.16 is a good example of this, as is Scent Of The Obscene from 0.10 to 0.45, and Hold My Finger during the intro and at 0.32. However, in more melodic numbers and moments, such as In This Light, Tupelo and Can’t We All Dream, the bass is content to kick with the bass drum or take the more atmospheric approach of using a greater number of root notes and simple and compound rhythms.
The lasting impression of Sikth is that of a band in which all instruments have been given equal consideration, and of a resulting versatility born from this egalitarian approach. Under distorted guitars, rough vocals and busy drums, the last instrument to be heard in heavy metal is often the bass. Yet despite all of the aforementioned factors being present (even more so than usual with an extra vocalist), with Sikth there is no sense of relegation when it comes to the bass. They can be a harsh listen, and are (well, would be) one of the last bands I use to introduce someone to heavy music (ease them in, nice and slowly, then when they’re settled, bam, the old fork in the eye). But this is partially because of their unique take on music, including a bass discontent to tread the common path.