Need help concat multiple fields into one based off of other fields

I asked a similar question recently but, unfortunately, the nature of the request changed. Been looking at this code for a bit but my brain is friend and I can't quite think of a way to get this working as needed.

Working in SQL 2005 and this will encompass hundreds of values like this.

Thanks in advance!

Sample Table

+----+-------------+---------------------+---------------------+
| ID |    CLASS    |  PARENT_ATTRIBUTE   |      ATTRIBUTE      |
+----+-------------+---------------------+---------------------+
|  1 | Genre       | A                   | Hip Hop             |
|  1 | Genre       | B                   | Pop                 |
|  1 | Instruments | Keyboards           | Synth               |
|  1 | Instruments | Keyboards           | Grand Piano         |
|  1 | Instruments | Drums               | Kit                 |
|  1 | Moods       | Positive/Optimistic | Uplifting/Inspiring |
|  1 | Moods       | Positive/Optimistic | Happy/Feel Good     |
|  1 | Moods       | Musical Feel        | Pulsing             |
+----+-------------+---------------------+---------------------+

Desired Output

+----+----------------------------------------------------------------------------------------------------------+---------------------------------------------------------+
| ID | MOODS                                                                                                    | INSTRUMENTS                                             |
| 1  |Positive/Optimistic - Uplifting/Inspiring, Positive/Optimistic -  Happy/Feel Good, Musical Feel - Pulsing | Keyboards - Synth, Keyboards - Grand Piano, Drums - Kit |
+----+----------------------------------------------------------------------------------------------------------+---------------------------------------------------------+