Invalid top-level element "string"

Hi

Google tells me that this page has unparsable structured data, e.g. ‘invalid top level element string’

{
    "@context": "http://schema.org",
    "@type": "Product",
    "aggregateRating": {
        "@type": "AggregateRating",
        "ratingValue": "4.5",
        "reviewCount": "2"
    },
    "name":"Adele for Piano Solo - 3rd Edition",
    "image":[""] }

Can you please explain how I can fix this error?