Possible Clues:

• One wooing with song
• One who might play under a balcony
• Lovesick guitarist perhaps needs rear kicked
• See a nerd travelling on river, one singing of love?
• He may be looked down on by the girl he woos
• The German goes after the girl - a musical swain
• Performer who may be calmer having grabbed a date
• He plays to capture heart and so win hand
• Plucky chap raising voice to sweetheart?
• Guitar player outside window