For one, the wonderful basslines of Motown make it easy. And standout players in genres like funk, soul and neo-soul, R&B, and prog rock also make it fun to examine that low-end magic happening just beneath the surface. But throughout the 1960s and ’70s, where the songwriter reigned as king — seconded (if even) only by that of the heaven-descended lead guitarist — bassists were mostly criminally ignored.
The resources in timbre are also quite limited, as the piece is composed for a single instrument. The piano is a great instrument with regards to dynamic range, but not quite as versatile in terms of timbre. The problem that springs from these limitations, especially the first, is how to fulfil the needs of a musical composition to provide enough variety so that the music would engage the listener, have forward momentum, and contain a sense of tension and resolution, which is fundamental for musical syntax.