Possible Clues:

• What auditioner's do (2 words)
• You start tucking into fish as an experiment
• What "merican Idol"singers must do first (2 words)
• Test for suitability
• Test for a non-specific factor in fish
• Sample fish stuffed with something unknown
• Put to the test
• Audition for a part
• Shrub depicted on Corinthian capitals
• Test run