Final answer:
The false statement among the choices is the 'rigid adherence to written arrangements'. Soloists in the Swing Era were celebrated for their improvisation skills and not confined strictly to written music.
Step-by-step explanation:
The Swing Era was characterized by jazz music with a focus on swing rhythms, big bands, and improvisation. Soloists in this music era were known for their ability to improvise and their strong sense of swing rhythm. Swing bands often followed arranged music to provide a framework, but were also well-known for their soloists' improvisational skills, which meant that there was not a rigid adherence to written arrangements. Instead, soloists had the creative freedom to add their own style and flair to performances, often in contrast to more traditional classical music of the time or earlier forms of band-led music that were more strict in their adherence to composed music.