The Maroon 5 singer was joined by his bandmates and Fleetwood Mac star Stevie Nicks to serenade guests at Flora Farms in Los Cabos, Mexico, on July 19, and the Victoria's Secret model later took to the stage, dedicating her rendition of Bright Eyes' track 'First Day of My Life' to her new husband.
One guest said: ''Everyone cheered for her.''
And the musical performances didn't stop with the newlyweds, as ska punk band Sublime also treated guests to some tracks.
Another guest told People magazine: ''This was a dancing crowd. Everyone was dancing late into the night.''
In between the music, there were also several speeches which had ''guests laughing''.
Those at the reception sat at large circular tables around big mango trees - which were decorated with floral garlands and tiny white lights which looked like fireflies - and severed a feast of organic pork chops, fresh fish and beet salads.
Later, an organic ice cream cart served desserts, which included alcohol-flavoured paletas, Mexican ice lollies.
One onlooker observed: ''Most people finished eating in under an hour and were ready to party...
''Everyone was having so much fun. Adam and Behati didn't stop smiling the entire night.''
He also slapped a jet-lagged Taylor Hawkins.
The acclaimed performer had just cancelled touring due to a battle with cancer.
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