  - (NSSet *) lookUpTitle: (NSString *)aName {      NSString *filters = @"%K CONTAINS [cd] %@";     NSPredicate *filter = [NSPredicate predicateWithFormat:filters, @"title", aName];      NSSet *result = [masterSongs filteredSetUsingPredicate:filter];      if ([result count] == 0) {         NSLog(@"not found");          return nil;     }     else{         return result;     } }  