unicorn.pidが原因でrailsアプリがデプロイできない

EC2よりrailsアプリをデプロイしようと考えています。

bundle exec unicorn_rails -c /var/www/rails/music_app/config/unicorn.conf.rb -D -E production　の後に
Elsaticアドレスをブラウザでたたいたところ応答がなかったためlog/unicorn.pidをみたところ以下のエラーが出てきました。

[ec2-user@ip-10-0-0-181 log]$ vi unicorn.log
I, [2020-11-25T11:49:01.522140 #11588]  INFO -- : Refreshing Gem list
I, [2020-11-25T11:49:03.559958 #11588]  INFO -- : listening on addr=/var/www/rails/music_app/tmp/sockets/.unicorn.sock fd=8
I, [2020-11-25T11:49:03.602171 #11588]  INFO -- : master process ready
I, [2020-11-25T11:49:03.610534 #11594]  INFO -- : worker=1 ready
I, [2020-11-25T11:49:03.611615 #11592]  INFO -- : worker=0 ready
I, [2020-11-25T12:37:05.403432 #11588]  INFO -- : reaped #<Process::Status: pid 11592 exit 0> worker=0
I, [2020-11-25T12:37:05.403529 #11588]  INFO -- : reaped #<Process::Status: pid 11594 exit 0> worker=1
I, [2020-11-25T12:37:05.403596 #11588]  INFO -- : master complete
I, [2020-11-25T12:38:31.094288 #12421]  INFO -- : Refreshing Gem list
I, [2020-11-25T12:38:32.659186 #12421]  INFO -- : unlinking existing socket=/var/www/rails/music_app/tmp/sockets/.unicorn.sock
I, [2020-11-25T12:38:32.659361 #12421]  INFO -- : listening on addr=/var/www/rails/music_app/tmp/sockets/.unicorn.sock fd=8
I, [2020-11-25T12:38:32.692011 #12421]  INFO -- : master process ready
I, [2020-11-25T12:38:32.698648 #12425]  INFO -- : worker=0 ready
I, [2020-11-25T12:38:32.700654 #12427]  INFO -- : worker=1 ready
I, [2020-11-25T13:06:09.143465 #12421]  INFO -- : reaped #<Process::Status: pid 12425 exit 0> worker=0
I, [2020-11-25T13:06:09.143563 #12421]  INFO -- : reaped #<Process::Status: pid 12427 exit 0> worker=1
I, [2020-11-25T13:06:09.143626 #12421]  INFO -- : master complete
I, [2020-11-25T13:06:25.498304 #12813]  INFO -- : Refreshing Gem list
I, [2020-11-25T13:06:27.057117 #12813]  INFO -- : unlinking existing socket=/var/www/rails/music_app/tmp/sockets/.unicorn.sock
I, [2020-11-25T13:06:27.057288 #12813]  INFO -- : listening on addr=/var/www/rails/music_app/tmp/sockets/.unicorn.sock fd=8
I, [2020-11-25T13:06:27.086848 #12813]  INFO -- : master process ready
I, [2020-11-25T13:06:27.093492 #12817]  INFO -- : worker=0 ready
I, [2020-11-25T13:06:27.095438 #12819]  INFO -- : worker=1 ready
bundler: failed to load command: unicorn_rails (/home/ec2-user/.rbenv/versions/2.5.3/bin/unicorn_rails)
ArgumentError: Already running on PID:12813 (or pid=/var/www/rails/music_app/tmp/pids/unicorn.pid is stale)
  /home/ec2-user/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/unicorn-5.7.0/lib/unicorn/http_server.rb:207:in `pid='
  /home/ec2-user/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/unicorn-5.7.0/lib/unicorn/http_server.rb:139:in `start'
  /home/ec2-user/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/unicorn-5.7.0/bin/unicorn_rails:209:in `<top (required)>'
  /home/ec2-user/.rbenv/versions/2.5.3/bin/unicorn_rails:23:in `load'
  /home/ec2-user/.rbenv/versions/2.5.3/bin/unicorn_rails:23:in `<top (required)>'
bundler: failed to load command: unicorn_rails (/home/ec2-user/.rbenv/versions/2.5.3/bin/unicorn_rails)
ArgumentError: Already running on PID:12813 (or pid=/var/www/rails/music_app/tmp/pids/unicorn.pid is stale)
  /home/ec2-user/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/unicorn-5.4.1/lib/unicorn/http_server.rb:205:in `pid='
  /home/ec2-user/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/unicorn-5.4.1/lib/unicorn/http_server.rb:137:in `start'

pid:12813が原因だと思ったので

terminal
1[ec2-user@ip-10-0-0-181 log]$ ps aux | grep 12813
2ec2-user 19682  0.0  0.0 119420   952 pts/0    S+   11:59   0:00 grep --color=auto 12813

19682をkillしようとしたのですが以下のように返されてしまいます。

terminal
1[ec2-user@ip-10-0-0-181 log]$ kill 19682
2-bash: kill: (19682) - No such process
3

unicorn.conf.rbの設定ミスでエラーが出てしまっているのかわからず、困惑しております。。
分かる方がいれば教えていただけないでしょうか。。

unicorn
1# set lets
2  $worker  = 2
3  $timeout = 30
4  $app_dir = "/var/www/rails/music_app"
5  $listen  = File.expand_path 'tmp/sockets/.unicorn.sock', $app_dir
6  $pid     = File.expand_path 'tmp/pids/unicorn.pid', $app_dir
7  $std_log = File.expand_path 'log/unicorn.log', $app_dir
8  # set config
9  worker_processes  $worker
10  working_directory $app_dir
11  stderr_path $std_log
12  stdout_path $std_log
13  timeout $timeout
14  listen  $listen
15  pid $pid
16  # loading booster
17  preload_app true
18  # before starting processes
19  before_fork do |server, worker|
20    defined?(ActiveRecord::Base) and ActiveRecord::Base.connection.disconnect!
21    old_pid = "#{server.config[:pid]}.oldbin"
22    if old_pid != server.pid
23      begin
24        Process.kill "QUIT", File.read(old_pid).to_i
25      rescue Errno::ENOENT, Errno::ESRCH
26      end
27    end
28  end
29  # after finishing processes
30  after_fork do |server, worker|
31    defined?(ActiveRecord::Base) and ActiveRecord::Base.establish_connection
32  end