Possible Clues:

• Mournful poet
• Composer of mournful poems
• Blue bard
• English member is first to thank one expressing mournful thoughts
• Gray is one for example appearing in computer catalogue?
• Writer, say, English are inclined to defend say
• Gloomy poet, say, enthralled by fifth-rate celebrities?
• Poet's line, for example, is in French also
• Part of the leg is theme for poet
• Glee? It’s unusual for this writer