Loader

  <div class='music'>
    <div class='bar'></div>
    <div class='bar'></div>
    <div class='bar'></div>
    <div class='bar'></div>
    <div class='bar'></div>
    <div class='bar'></div>
    <div class='bar'></div>
    <div class='bar'></div>
    <div class='bar'></div>
    <div class='bar'></div>
  </div>

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  background-color: black;
}

.music {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
  width: 300px;
  height: 200px;
}

.music .bar {
  width: 12px;
  height: 2px;
  border-radius: 10px;
  background-color: white;
  animation: up_down 1.5s ease-in-out infinite;
}

@keyframes up_down {
  0%,
  100% {
    height: 2px;
  }
  50% {
    height: 80px;
  }
}

.music .bar:nth-child(1) {
  background-color: purple;
  animation-delay: 1s;
}

.music .bar:nth-child(2) {
  background-color: crimson;
  animation-delay: 0.8s;
}

.music .bar:nth-child(3) {
  background-color: deeppink;
  animation-delay: 0.6s;
}

.music .bar:nth-child(4) {
  background-color: orange;
  animation-delay: 0.4s;
}

.music .bar:nth-child(5) {
  background-color: gold;
  animation-delay: 0.2s;
}

.music .bar:nth-child(6) {
  background-color: gold;
  animation-delay: 0.2s;
}

.music .bar:nth-child(7) {
  background-color: orange;
  animation-delay: 0.4s;
}

.music .bar:nth-child(8) {
  background-color: deeppink;
  animation-delay: 0.6s;
}

.music .bar:nth-child(9) {
  background-color: crimson;
  animation-delay: 0.8s;
}

.music .bar:nth-child(10) {
  background-color: purple;
  animation-delay: 1s;
}