CREATE TABLE "singer" (
"Singer_ID" int,
"Name" text,
"Birth_Year" real,
"Net_Worth_Millions" real,
"Citizenship" text,
PRIMARY KEY ("Singer_ID")
)

CREATE TABLE "song" (
"Song_ID" int,
"Title" text,
"Singer_ID" int,
"Sales" real,
"Highest_Position" real,
PRIMARY KEY ("Song_ID"),
FOREIGN KEY ("Singer_ID") REFERENCES `singer`("Singer_ID")
)
SELECT DISTINCT T1.Name FROM singer AS T1 JOIN song AS T2 ON T1.Singer_ID  =  T2.Singer_ID WHERE T2.Sales  >  300000
what are the different names of the singers that have sales more than 300000?