VIKRAM Seth is making a big splash in Singapore. This time, for his opera, Arion and the Dolphin, which is to be performed by the Singapore Symphony Orchestra (SSO) from June 29 to July 1 as part of the annual Festival of the Arts in the island republic. In a unique and expensive experiment which began last year, author Seth, British composer Alec Roth, the SSO and Singapore secondary school and junior college students, with help from the British Council, worked hard on a presentation of Seth's charming verse libretto which is expected to be showcased in a packed Victoria Theatre. Cost: (Singapore) $250,000.