It sounds like a Sopranos plot: Tony leans on a judge to fuhgeddaboudit after his sulky son, A.J., gets busted for allegedly muscling two teens out of $30. 

Only this father-and-son drama is for real. 

A judge yesterday set a May 6 robbery trial date for 16-year-old Sopranos star Robert Iler unswayed by a polite letter from actor James Gandolfini, Iler's dangerous don daddy on the hit HBO show. 

Gandolfini had written Manhattan Supreme Court Justice Bonnie Wittner on Iler's behalf as part of a failed defense effort to get the case tossed in the interest of justice. 

Iler faces up to 15 years prison if convicted of charges he joined three other teens in the midnight mugging of two boys at East 74th Street and York Avenue last July. 

Iler is heading for trial after turning down the DA's offer of a no-jail plea, because the deal would require him to admit he's a mugger  something sources say he refuses to do. 

Gandolfini's letter  included in Iler's court file along with letters of praise from his tutor and from a Catholic charity for which the teen has raised money was written in October but only recently made part of the public record. 

It would disappoint fans of Gandolfini's nefarious TV character, having not the faintest hint of "Tony" in it  no threats to the kneecaps, no non-refusable offers, not even a sneering insinuation, although Gandolfini does praise his TV kid's "respect for others." 

The judge has given Iler the right to argue in an upcoming hearing that cops wrongly coerced his statements and seized pot from his pocket.

For more news, entertainment and sports coverage, click here for NYPost.com.