In some ways, 1973 was a little early for Rod Stewart to release a greatest-hits album, since he had only released four albums to that point.
Nevertheless, Sing It Again Rod is a good collection, featuring most of the obvious choices from his first four records -- "Handbags and Gladrags," "Street Fighting Man," "Gasoline Alley," "You Wear It Well" and a full side of Every Picture Tells a Story ("Maggie May," "Mandolin Wind," "Reason to Believe," "(I Know) I'm Losing You") -- plus nice surprises like "Lost Paraguayos" and his version of "Pinball Wizard," which had yet to appear on a Stewart record.
It's an entertaining album, but it's a little useless for anyone except the most casual fans, those who just want hits.
Anyone else would be better served by the original albums, all of which are superb.