arrayToUniqObj.js

const records = [
  { title: "The Clash", artist: "The Clash", type: "LP", lengthSec: 2220, released: "1977"},
  { title: "Rocket to Russia", artist: "Ramones", type: "LP", lengthSec: 1906, released: "1977"},
  ...etc
];

// es5
const way = records.reduce((acc, record) => {
  acc[`${record.title} - ${record.artist}`] = record;
  
  return acc;
}, {});

// es6
const way = records.reduce((acc, record) => ({
  ...acc,
  [`${record.title} - ${record.artist}`]: record,
}), {});
/* 
=> { 
  "The Clash - The Clash": { artist: "The Clash", lengthSec: 2220, released: "1977", title: "The Clash", type: "LP"},
  "Rocket to Russia - Ramones": { artist: "Ramones", lengthSec: 1906, realease: "1977",  title: "Rocket to Russia", type: "LP"},
}
*/