Final answer:
Hall & Oates, while embodying a sound with R&B and soul influences similar to acts from the 60s, are best classified as Pop bands due to their mainstream appeal and fusion of various musical styles.
Step-by-step explanation:
Bands like Hall & Oates, which echoed the soulful and R&B sound reminiscent of the 60's acts like the Righteous Brothers, are generally classified as Pop bands. This era's music was marked by its roots in traditional rhythm and blues and its evolution into new forms. Historical shifts saw the fusion of gospel, blues, country, jazz, and R&B, which gave rise to the rock and roll phenomenon. Against this backdrop, Hall & Oates and similar bands achieved their fame blending soulful melodies with a mainstream pop appeal, earning them a place within the pop music sphere rather than strictly being an R&B bands or the more rugged style usually associated with rock bands.
To clarify further, the broad term 'pop' is derived from 'popular' music and can encompass a wide range of styles, including elements from rock, R&B, and others, thus making it the most suitable label for Hall & Oates when considering their wide appeal and cross-genre influences.